linux/drivers/soundwire/intel.c

2024 lines
51 KiB

soundwire: cadence: add paranoid check on self-clearing bits The Cadence IP exposes a small number of self-clearing bits in the MCP_CONTROL and MCP_CONFIG_UPDATE registers. We currently do not check that those bits are indeed cleared, e.g. during resume operations. That could lead to resuming peripheral devices too early. In addition, if we happen to read these registers, update one of the fields and write the register back, we may be writing stale data that might have been cleared in hardware. These sort of race conditions could lead to e.g. doing a hw_reset twice or stopping a clock that just restarted. There is no clear way of avoiding these potential race conditions other than making sure that these registers fields are cleared before any read-modify-write sequence. If we detect this sort of errors, we only log them since there is no clear recovery possible. The only way out is likely to restart the IP with a suspend/resume cycle. Note that the checks are performed before updating the registers, as well as after the Intel 'sync go' sequence in multi-link mode. That should cover both the start and end of suspend/resume hardware configurations. The Multi-Master mode gates the configuration updates until the 'sync go' signal is asserted, so we only check on init and after the end of the 'sync go' sequence. The duration of the usleep_range() was defined by the GSYNC frequency used in multi-master mode. With a 4kHz frequency, any configuration change might be deferred by up to 250us. Extending the range to 1000-1500us should guarantee that the configuration change is completed without any significant impact on the overall resume time. Suggested-by: Bard Liao <yung-chuan.liao@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210714051349.13064-1-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-07-14 13:13:49 +08:00
soundwire: intel: improve suspend flows This patch provides both a simplification of the suspend flows and a better balanced operation during suspend/resume transition, as part of the transition of Sound Open Firmware (SOF) to dynamic pipelines: the DSP resources are only enabled when required instead of enabled on startup. The exiting code relies on a convoluted way of dealing with suspend signals. Since there is no .suspend DAI callback, we used the component .suspend and marked all the component DAI dmas as 'suspended'. The information was used in the .prepare stage to differentiate resume operations from xrun handling, and only reinitialize SHIM registers and DMA in the former case. While this solution has been working reliably for about 2 years, there is a much better solution consisting in trapping the TRIGGER_SUSPEND in the .trigger DAI ops. The DMA is still marked in the same way for the .prepare op to run, but in addition the callbacks sent to DSP firmware are now balanced. Normal operation: hw_params -> intel_params_stream hw_free -> intel_free_stream suspend -> intel_free_stream prepare -> intel_params_stream This balanced operation was not required with existing SOF firmware relying on static pipelines instantiated at every boot. With the on-going transition to dynamic pipelines, it's however a requirement to keep the use count for the DAI widget balanced across all transitions. The component suspend is not removed but instead modified to deal with a corner case: when a substream is PAUSED, the ALSA core does not throw the TRIGGER_SUSPEND. This is problematic since the refcount for all pipelines and widgets is not balanced, leading to issues on resume. The trigger callback keeps track of the 'paused' state with a new flag, which is tested during the component suspend called later to release the remaining DSP resources. These resources will be re-enabled in the .prepare step. The IPC used in the TRIGGER_SUSPEND to release DSP resources is not a problem since the BE dailink is already marked as non-atomic. Co-developed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Acked-By: Vinod Koul <vkoul@kernel.org> Link: https://lore.kernel.org/r/20211224021034.26635-4-yung-chuan.liao@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
2021-12-24 10:10:30 +08:00
soundwire: intel: improve suspend flows This patch provides both a simplification of the suspend flows and a better balanced operation during suspend/resume transition, as part of the transition of Sound Open Firmware (SOF) to dynamic pipelines: the DSP resources are only enabled when required instead of enabled on startup. The exiting code relies on a convoluted way of dealing with suspend signals. Since there is no .suspend DAI callback, we used the component .suspend and marked all the component DAI dmas as 'suspended'. The information was used in the .prepare stage to differentiate resume operations from xrun handling, and only reinitialize SHIM registers and DMA in the former case. While this solution has been working reliably for about 2 years, there is a much better solution consisting in trapping the TRIGGER_SUSPEND in the .trigger DAI ops. The DMA is still marked in the same way for the .prepare op to run, but in addition the callbacks sent to DSP firmware are now balanced. Normal operation: hw_params -> intel_params_stream hw_free -> intel_free_stream suspend -> intel_free_stream prepare -> intel_params_stream This balanced operation was not required with existing SOF firmware relying on static pipelines instantiated at every boot. With the on-going transition to dynamic pipelines, it's however a requirement to keep the use count for the DAI widget balanced across all transitions. The component suspend is not removed but instead modified to deal with a corner case: when a substream is PAUSED, the ALSA core does not throw the TRIGGER_SUSPEND. This is problematic since the refcount for all pipelines and widgets is not balanced, leading to issues on resume. The trigger callback keeps track of the 'paused' state with a new flag, which is tested during the component suspend called later to release the remaining DSP resources. These resources will be re-enabled in the .prepare step. The IPC used in the TRIGGER_SUSPEND to release DSP resources is not a problem since the BE dailink is already marked as non-atomic. Co-developed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Acked-By: Vinod Koul <vkoul@kernel.org> Link: https://lore.kernel.org/r/20211224021034.26635-4-yung-chuan.liao@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
2021-12-24 10:10:30 +08:00
soundwire: intel: improve suspend flows This patch provides both a simplification of the suspend flows and a better balanced operation during suspend/resume transition, as part of the transition of Sound Open Firmware (SOF) to dynamic pipelines: the DSP resources are only enabled when required instead of enabled on startup. The exiting code relies on a convoluted way of dealing with suspend signals. Since there is no .suspend DAI callback, we used the component .suspend and marked all the component DAI dmas as 'suspended'. The information was used in the .prepare stage to differentiate resume operations from xrun handling, and only reinitialize SHIM registers and DMA in the former case. While this solution has been working reliably for about 2 years, there is a much better solution consisting in trapping the TRIGGER_SUSPEND in the .trigger DAI ops. The DMA is still marked in the same way for the .prepare op to run, but in addition the callbacks sent to DSP firmware are now balanced. Normal operation: hw_params -> intel_params_stream hw_free -> intel_free_stream suspend -> intel_free_stream prepare -> intel_params_stream This balanced operation was not required with existing SOF firmware relying on static pipelines instantiated at every boot. With the on-going transition to dynamic pipelines, it's however a requirement to keep the use count for the DAI widget balanced across all transitions. The component suspend is not removed but instead modified to deal with a corner case: when a substream is PAUSED, the ALSA core does not throw the TRIGGER_SUSPEND. This is problematic since the refcount for all pipelines and widgets is not balanced, leading to issues on resume. The trigger callback keeps track of the 'paused' state with a new flag, which is tested during the component suspend called later to release the remaining DSP resources. These resources will be re-enabled in the .prepare step. The IPC used in the TRIGGER_SUSPEND to release DSP resources is not a problem since the BE dailink is already marked as non-atomic. Co-developed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Acked-By: Vinod Koul <vkoul@kernel.org> Link: https://lore.kernel.org/r/20211224021034.26635-4-yung-chuan.liao@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
2021-12-24 10:10:30 +08:00
soundwire: intel: improve suspend flows This patch provides both a simplification of the suspend flows and a better balanced operation during suspend/resume transition, as part of the transition of Sound Open Firmware (SOF) to dynamic pipelines: the DSP resources are only enabled when required instead of enabled on startup. The exiting code relies on a convoluted way of dealing with suspend signals. Since there is no .suspend DAI callback, we used the component .suspend and marked all the component DAI dmas as 'suspended'. The information was used in the .prepare stage to differentiate resume operations from xrun handling, and only reinitialize SHIM registers and DMA in the former case. While this solution has been working reliably for about 2 years, there is a much better solution consisting in trapping the TRIGGER_SUSPEND in the .trigger DAI ops. The DMA is still marked in the same way for the .prepare op to run, but in addition the callbacks sent to DSP firmware are now balanced. Normal operation: hw_params -> intel_params_stream hw_free -> intel_free_stream suspend -> intel_free_stream prepare -> intel_params_stream This balanced operation was not required with existing SOF firmware relying on static pipelines instantiated at every boot. With the on-going transition to dynamic pipelines, it's however a requirement to keep the use count for the DAI widget balanced across all transitions. The component suspend is not removed but instead modified to deal with a corner case: when a substream is PAUSED, the ALSA core does not throw the TRIGGER_SUSPEND. This is problematic since the refcount for all pipelines and widgets is not balanced, leading to issues on resume. The trigger callback keeps track of the 'paused' state with a new flag, which is tested during the component suspend called later to release the remaining DSP resources. These resources will be re-enabled in the .prepare step. The IPC used in the TRIGGER_SUSPEND to release DSP resources is not a problem since the BE dailink is already marked as non-atomic. Co-developed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Acked-By: Vinod Koul <vkoul@kernel.org> Link: https://lore.kernel.org/r/20211224021034.26635-4-yung-chuan.liao@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
2021-12-24 10:10:30 +08:00
ASoC/SoundWire: dai: expand 'stream' concept beyond SoundWire The HDAudio ASoC support relies on the set_tdm_slots() helper to store the HDaudio stream tag in the tx_mask. This only works because of the pre-existing order in soc-pcm.c, where the hw_params() is handled for codec_dais *before* cpu_dais. When the order is reversed, the stream_tag is used as a mask in the codec fixup functions: /* fixup params based on TDM slot masks */ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && codec_dai->tx_mask) soc_pcm_codec_params_fixup(&codec_params, codec_dai->tx_mask); As a result of this confusion, the codec_params_fixup() ends-up generating bad channel masks, depending on what stream_tag was allocated. We could add a flag to state that the tx_mask is really not a mask, but it would be quite ugly to persist in overloading concepts. Instead, this patch suggests a more generic get/set 'stream' API based on the existing model for SoundWire. We can expand the concept to store 'stream' opaque information that is specific to different DAI types. In the case of HDAudio DAIs, we only need to store a stream tag as an unsigned char pointer. The TDM rx_ and tx_masks should really only be used to store masks. Rename get_sdw_stream/set_sdw_stream callbacks and helpers as get_stream/set_stream. No functionality change beyond the rename. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Reviewed-by: Rander Wang <rander.wang@intel.com> Reviewed-by: Ranjani Sridharan <ranjani.sridharan@intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Acked-By: Vinod Koul <vkoul@kernel.org> Link: https://lore.kernel.org/r/20211224021034.26635-5-yung-chuan.liao@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
2021-12-24 10:10:31 +08:00
soundwire: intel: prevent pm_runtime resume prior to system suspend commit e38f9ff63e6d ("ACPI: scan: Do not add device IDs from _CID if _HID is not valid") exposes a race condition on a TGL RVP device leading to a timeout. The detailed analysis shows the RT711 codec driver scheduling a jack detection workqueue while attaching during a spurious pm_runtime resume, and the work function happens to be scheduled after the manager device is suspended. The direct link between this ACPI patch and a spurious pm_runtime resume is not obvious; the most likely explanation is that a change in the ACPI device linked list management modifies the order in which the pm_runtime device status is checked and exposes a race condition that was probably present for a very long time, but was not identified. We already have a check in the .prepare stage, where we will resume to full power from specific clock-stop modes. In all other cases, we don't need to resume to full power by default. Adding the SMART_SUSPEND flag prevents the spurious resume from happening. BugLink: https://github.com/thesofproject/linux/issues/3459 Fixes: 029bfd1cd53cd ("soundwire: intel: conditionally exit clock stop mode on system suspend") Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Reviewed-by: Rander Wang <rander.wang@intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20220420023241.14335-2-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2022-04-20 10:32:39 +08:00
soundwire: cadence: add paranoid check on self-clearing bits The Cadence IP exposes a small number of self-clearing bits in the MCP_CONTROL and MCP_CONFIG_UPDATE registers. We currently do not check that those bits are indeed cleared, e.g. during resume operations. That could lead to resuming peripheral devices too early. In addition, if we happen to read these registers, update one of the fields and write the register back, we may be writing stale data that might have been cleared in hardware. These sort of race conditions could lead to e.g. doing a hw_reset twice or stopping a clock that just restarted. There is no clear way of avoiding these potential race conditions other than making sure that these registers fields are cleared before any read-modify-write sequence. If we detect this sort of errors, we only log them since there is no clear recovery possible. The only way out is likely to restart the IP with a suspend/resume cycle. Note that the checks are performed before updating the registers, as well as after the Intel 'sync go' sequence in multi-link mode. That should cover both the start and end of suspend/resume hardware configurations. The Multi-Master mode gates the configuration updates until the 'sync go' signal is asserted, so we only check on init and after the end of the 'sync go' sequence. The duration of the usleep_range() was defined by the GSYNC frequency used in multi-master mode. With a 4kHz frequency, any configuration change might be deferred by up to 250us. Extending the range to 1000-1500us should guarantee that the configuration change is completed without any significant impact on the overall resume time. Suggested-by: Bard Liao <yung-chuan.liao@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210714051349.13064-1-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-07-14 13:13:49 +08:00
soundwire: intel: skip suspend/resume/wake when link was not started The SoundWire Linux devices are created purely based on information provided by platform firmware (e.g. ACPI DSDT table). When the kernel finds a matching driver for the device address (_ADR), the probe will initialize required data structures and initialize pm ops. When the SoundWire link is started at a later point, the physical devices will synchronize on the SoundWire frames and report their attachment status, thereby triggering the enumeration and initialization of device registers. This two-step solution was a conscious design decision to allow e.g. a driver to use sideband mechanisms to turn power rails on. This can also allow OEMs to describe multiple platforms with the same DSDT table, the devices that are not physically present in hardware. The drawback of this approach is a bit of confusion, with more devices than are actually present in hardware. This results in 'ghost' devices, for which the driver successfully probes, but that will not generate any traffic on the bus. suspend-resume transitions are handled by drivers, and skipped when the devices are not physically present. This patch provides a work-around for a second-level of confusion in platform firmware: some platforms only use HDaudio links, but nevertheless expose SoundWire 'ghost' devices. This results in error messages in the Intel driver while trying to suspend/resume these links. The simplest solution is to add a boolean status flag to skip all suspend/resume/wake sequences if the link was never started. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210818024954.16873-3-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-08-18 10:49:53 +08:00
soundwire: intel: skip suspend/resume/wake when link was not started The SoundWire Linux devices are created purely based on information provided by platform firmware (e.g. ACPI DSDT table). When the kernel finds a matching driver for the device address (_ADR), the probe will initialize required data structures and initialize pm ops. When the SoundWire link is started at a later point, the physical devices will synchronize on the SoundWire frames and report their attachment status, thereby triggering the enumeration and initialization of device registers. This two-step solution was a conscious design decision to allow e.g. a driver to use sideband mechanisms to turn power rails on. This can also allow OEMs to describe multiple platforms with the same DSDT table, the devices that are not physically present in hardware. The drawback of this approach is a bit of confusion, with more devices than are actually present in hardware. This results in 'ghost' devices, for which the driver successfully probes, but that will not generate any traffic on the bus. suspend-resume transitions are handled by drivers, and skipped when the devices are not physically present. This patch provides a work-around for a second-level of confusion in platform firmware: some platforms only use HDaudio links, but nevertheless expose SoundWire 'ghost' devices. This results in error messages in the Intel driver while trying to suspend/resume these links. The simplest solution is to add a boolean status flag to skip all suspend/resume/wake sequences if the link was never started. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210818024954.16873-3-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-08-18 10:49:53 +08:00
soundwire: intel: conditionally exit clock stop mode on system suspend Intel stress tests reported issues with the clock stop mode, specifically when trying to do a system suspend while the link is already pm_runtime suspended. In this case, we need to disable the shim wake, but when the PCI parent device is also pm_runtime suspended the SHIM registers are not accessible. Since this is an invalid corner case, this patch suggests a pm_runtime resume of the entire bus to full power (parent+child devices) before the system suspend so that the shim wake can be disabled. Unlike the suspend operation, the .prepare callbacks are propagated from root device to leaf devices. By adding a .prepare callback at the SoundWire link level, we can double-check the pm_runtime status of the device as well as its parent PCI device. When the problematic configuration is detected, the device is pm_runtime resumed - which by construction also resume its parent. An additional loop is added to resume all child devices. In theory we only need to restart the link, but doing so will also cause the physical devices to synchronize and re-initialize, while their Linux devices remain pm_runtime suspended. It's simpler to make sure the codec devices are fully resumed so that we don't have to deal with zombie states. This additional loop could have been avoided by adding a .prepare callback in SoundWire codec drivers. Functionally this would have been equivalent. The rationale for implementing a loop at the link level is only to reduce the amount of code required to deal at the codec level with an Intel corner case - in other words keep codec drivers independent from Intel platform-specific programming sequences. BugLink: https://github.com/thesofproject/linux/issues/2606 Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210818024954.16873-4-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-08-18 10:49:54 +08:00
soundwire: intel: conditionally exit clock stop mode on system suspend Intel stress tests reported issues with the clock stop mode, specifically when trying to do a system suspend while the link is already pm_runtime suspended. In this case, we need to disable the shim wake, but when the PCI parent device is also pm_runtime suspended the SHIM registers are not accessible. Since this is an invalid corner case, this patch suggests a pm_runtime resume of the entire bus to full power (parent+child devices) before the system suspend so that the shim wake can be disabled. Unlike the suspend operation, the .prepare callbacks are propagated from root device to leaf devices. By adding a .prepare callback at the SoundWire link level, we can double-check the pm_runtime status of the device as well as its parent PCI device. When the problematic configuration is detected, the device is pm_runtime resumed - which by construction also resume its parent. An additional loop is added to resume all child devices. In theory we only need to restart the link, but doing so will also cause the physical devices to synchronize and re-initialize, while their Linux devices remain pm_runtime suspended. It's simpler to make sure the codec devices are fully resumed so that we don't have to deal with zombie states. This additional loop could have been avoided by adding a .prepare callback in SoundWire codec drivers. Functionally this would have been equivalent. The rationale for implementing a loop at the link level is only to reduce the amount of code required to deal at the codec level with an Intel corner case - in other words keep codec drivers independent from Intel platform-specific programming sequences. BugLink: https://github.com/thesofproject/linux/issues/2606 Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210818024954.16873-4-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-08-18 10:49:54 +08:00
soundwire: intel: skip suspend/resume/wake when link was not started The SoundWire Linux devices are created purely based on information provided by platform firmware (e.g. ACPI DSDT table). When the kernel finds a matching driver for the device address (_ADR), the probe will initialize required data structures and initialize pm ops. When the SoundWire link is started at a later point, the physical devices will synchronize on the SoundWire frames and report their attachment status, thereby triggering the enumeration and initialization of device registers. This two-step solution was a conscious design decision to allow e.g. a driver to use sideband mechanisms to turn power rails on. This can also allow OEMs to describe multiple platforms with the same DSDT table, the devices that are not physically present in hardware. The drawback of this approach is a bit of confusion, with more devices than are actually present in hardware. This results in 'ghost' devices, for which the driver successfully probes, but that will not generate any traffic on the bus. suspend-resume transitions are handled by drivers, and skipped when the devices are not physically present. This patch provides a work-around for a second-level of confusion in platform firmware: some platforms only use HDaudio links, but nevertheless expose SoundWire 'ghost' devices. This results in error messages in the Intel driver while trying to suspend/resume these links. The simplest solution is to add a boolean status flag to skip all suspend/resume/wake sequences if the link was never started. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210818024954.16873-3-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-08-18 10:49:53 +08:00
soundwire: intel: conditionally exit clock stop mode on system suspend Intel stress tests reported issues with the clock stop mode, specifically when trying to do a system suspend while the link is already pm_runtime suspended. In this case, we need to disable the shim wake, but when the PCI parent device is also pm_runtime suspended the SHIM registers are not accessible. Since this is an invalid corner case, this patch suggests a pm_runtime resume of the entire bus to full power (parent+child devices) before the system suspend so that the shim wake can be disabled. Unlike the suspend operation, the .prepare callbacks are propagated from root device to leaf devices. By adding a .prepare callback at the SoundWire link level, we can double-check the pm_runtime status of the device as well as its parent PCI device. When the problematic configuration is detected, the device is pm_runtime resumed - which by construction also resume its parent. An additional loop is added to resume all child devices. In theory we only need to restart the link, but doing so will also cause the physical devices to synchronize and re-initialize, while their Linux devices remain pm_runtime suspended. It's simpler to make sure the codec devices are fully resumed so that we don't have to deal with zombie states. This additional loop could have been avoided by adding a .prepare callback in SoundWire codec drivers. Functionally this would have been equivalent. The rationale for implementing a loop at the link level is only to reduce the amount of code required to deal at the codec level with an Intel corner case - in other words keep codec drivers independent from Intel platform-specific programming sequences. BugLink: https://github.com/thesofproject/linux/issues/2606 Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210818024954.16873-4-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-08-18 10:49:54 +08:00
soundwire: intel: skip suspend/resume/wake when link was not started The SoundWire Linux devices are created purely based on information provided by platform firmware (e.g. ACPI DSDT table). When the kernel finds a matching driver for the device address (_ADR), the probe will initialize required data structures and initialize pm ops. When the SoundWire link is started at a later point, the physical devices will synchronize on the SoundWire frames and report their attachment status, thereby triggering the enumeration and initialization of device registers. This two-step solution was a conscious design decision to allow e.g. a driver to use sideband mechanisms to turn power rails on. This can also allow OEMs to describe multiple platforms with the same DSDT table, the devices that are not physically present in hardware. The drawback of this approach is a bit of confusion, with more devices than are actually present in hardware. This results in 'ghost' devices, for which the driver successfully probes, but that will not generate any traffic on the bus. suspend-resume transitions are handled by drivers, and skipped when the devices are not physically present. This patch provides a work-around for a second-level of confusion in platform firmware: some platforms only use HDaudio links, but nevertheless expose SoundWire 'ghost' devices. This results in error messages in the Intel driver while trying to suspend/resume these links. The simplest solution is to add a boolean status flag to skip all suspend/resume/wake sequences if the link was never started. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210818024954.16873-3-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-08-18 10:49:53 +08:00
soundwire: intel: skip suspend/resume/wake when link was not started The SoundWire Linux devices are created purely based on information provided by platform firmware (e.g. ACPI DSDT table). When the kernel finds a matching driver for the device address (_ADR), the probe will initialize required data structures and initialize pm ops. When the SoundWire link is started at a later point, the physical devices will synchronize on the SoundWire frames and report their attachment status, thereby triggering the enumeration and initialization of device registers. This two-step solution was a conscious design decision to allow e.g. a driver to use sideband mechanisms to turn power rails on. This can also allow OEMs to describe multiple platforms with the same DSDT table, the devices that are not physically present in hardware. The drawback of this approach is a bit of confusion, with more devices than are actually present in hardware. This results in 'ghost' devices, for which the driver successfully probes, but that will not generate any traffic on the bus. suspend-resume transitions are handled by drivers, and skipped when the devices are not physically present. This patch provides a work-around for a second-level of confusion in platform firmware: some platforms only use HDaudio links, but nevertheless expose SoundWire 'ghost' devices. This results in error messages in the Intel driver while trying to suspend/resume these links. The simplest solution is to add a boolean status flag to skip all suspend/resume/wake sequences if the link was never started. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210818024954.16873-3-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-08-18 10:49:53 +08:00
soundwire: cadence: add paranoid check on self-clearing bits The Cadence IP exposes a small number of self-clearing bits in the MCP_CONTROL and MCP_CONFIG_UPDATE registers. We currently do not check that those bits are indeed cleared, e.g. during resume operations. That could lead to resuming peripheral devices too early. In addition, if we happen to read these registers, update one of the fields and write the register back, we may be writing stale data that might have been cleared in hardware. These sort of race conditions could lead to e.g. doing a hw_reset twice or stopping a clock that just restarted. There is no clear way of avoiding these potential race conditions other than making sure that these registers fields are cleared before any read-modify-write sequence. If we detect this sort of errors, we only log them since there is no clear recovery possible. The only way out is likely to restart the IP with a suspend/resume cycle. Note that the checks are performed before updating the registers, as well as after the Intel 'sync go' sequence in multi-link mode. That should cover both the start and end of suspend/resume hardware configurations. The Multi-Master mode gates the configuration updates until the 'sync go' signal is asserted, so we only check on init and after the end of the 'sync go' sequence. The duration of the usleep_range() was defined by the GSYNC frequency used in multi-master mode. With a 4kHz frequency, any configuration change might be deferred by up to 250us. Extending the range to 1000-1500us should guarantee that the configuration change is completed without any significant impact on the overall resume time. Suggested-by: Bard Liao <yung-chuan.liao@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210714051349.13064-1-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-07-14 13:13:49 +08:00
soundwire: intel: skip suspend/resume/wake when link was not started The SoundWire Linux devices are created purely based on information provided by platform firmware (e.g. ACPI DSDT table). When the kernel finds a matching driver for the device address (_ADR), the probe will initialize required data structures and initialize pm ops. When the SoundWire link is started at a later point, the physical devices will synchronize on the SoundWire frames and report their attachment status, thereby triggering the enumeration and initialization of device registers. This two-step solution was a conscious design decision to allow e.g. a driver to use sideband mechanisms to turn power rails on. This can also allow OEMs to describe multiple platforms with the same DSDT table, the devices that are not physically present in hardware. The drawback of this approach is a bit of confusion, with more devices than are actually present in hardware. This results in 'ghost' devices, for which the driver successfully probes, but that will not generate any traffic on the bus. suspend-resume transitions are handled by drivers, and skipped when the devices are not physically present. This patch provides a work-around for a second-level of confusion in platform firmware: some platforms only use HDaudio links, but nevertheless expose SoundWire 'ghost' devices. This results in error messages in the Intel driver while trying to suspend/resume these links. The simplest solution is to add a boolean status flag to skip all suspend/resume/wake sequences if the link was never started. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210818024954.16873-3-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-08-18 10:49:53 +08:00
soundwire: intel: disable WAKEEN in pm_runtime resume When the manager device is pm_runtime resumed, we see a series of spurious wakes and attempts to resume the same device: soundwire_intel.link.0: intel_resume_runtime: start soundwire_intel.link.0: intel_link_power_up: powering up all links soundwire_intel.link.0: intel_link_power_up: first link up, programming SYNCPRD soundwire_intel.link.0: intel_shim_wake: WAKEEN disabled for link 0 soundwire_intel.link.0: intel_link_process_wakeen_event: pm_request_resume start soundwire_intel.link.0: intel_link_process_wakeen_event: pm_request_resume done soundwire_intel.link.0: intel_shim_wake: WAKEEN disabled for link 0 soundwire_intel.link.0: intel_link_process_wakeen_event: pm_request_resume start soundwire_intel.link.0: intel_link_process_wakeen_event: pm_request_resume done This sequence does not break anything but is totally unnecessary. Currently the wakes are only disabled after the peripheral generates a wake, e.g. for jack detection. If the resume is initiated by the host drivers as a result of userspace actions (play/record typically), we need to disable wake detection as well. Doing so prevents the spurious wakes and calls to pm_request_resume(). Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Reviewed-by: Rander Wang <rander.wang@intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20220420023241.14335-3-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2022-04-20 10:32:40 +08:00
soundwire: cadence: add paranoid check on self-clearing bits The Cadence IP exposes a small number of self-clearing bits in the MCP_CONTROL and MCP_CONFIG_UPDATE registers. We currently do not check that those bits are indeed cleared, e.g. during resume operations. That could lead to resuming peripheral devices too early. In addition, if we happen to read these registers, update one of the fields and write the register back, we may be writing stale data that might have been cleared in hardware. These sort of race conditions could lead to e.g. doing a hw_reset twice or stopping a clock that just restarted. There is no clear way of avoiding these potential race conditions other than making sure that these registers fields are cleared before any read-modify-write sequence. If we detect this sort of errors, we only log them since there is no clear recovery possible. The only way out is likely to restart the IP with a suspend/resume cycle. Note that the checks are performed before updating the registers, as well as after the Intel 'sync go' sequence in multi-link mode. That should cover both the start and end of suspend/resume hardware configurations. The Multi-Master mode gates the configuration updates until the 'sync go' signal is asserted, so we only check on init and after the end of the 'sync go' sequence. The duration of the usleep_range() was defined by the GSYNC frequency used in multi-master mode. With a 4kHz frequency, any configuration change might be deferred by up to 250us. Extending the range to 1000-1500us should guarantee that the configuration change is completed without any significant impact on the overall resume time. Suggested-by: Bard Liao <yung-chuan.liao@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210714051349.13064-1-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-07-14 13:13:49 +08:00
soundwire: cadence: add paranoid check on self-clearing bits The Cadence IP exposes a small number of self-clearing bits in the MCP_CONTROL and MCP_CONFIG_UPDATE registers. We currently do not check that those bits are indeed cleared, e.g. during resume operations. That could lead to resuming peripheral devices too early. In addition, if we happen to read these registers, update one of the fields and write the register back, we may be writing stale data that might have been cleared in hardware. These sort of race conditions could lead to e.g. doing a hw_reset twice or stopping a clock that just restarted. There is no clear way of avoiding these potential race conditions other than making sure that these registers fields are cleared before any read-modify-write sequence. If we detect this sort of errors, we only log them since there is no clear recovery possible. The only way out is likely to restart the IP with a suspend/resume cycle. Note that the checks are performed before updating the registers, as well as after the Intel 'sync go' sequence in multi-link mode. That should cover both the start and end of suspend/resume hardware configurations. The Multi-Master mode gates the configuration updates until the 'sync go' signal is asserted, so we only check on init and after the end of the 'sync go' sequence. The duration of the usleep_range() was defined by the GSYNC frequency used in multi-master mode. With a 4kHz frequency, any configuration change might be deferred by up to 250us. Extending the range to 1000-1500us should guarantee that the configuration change is completed without any significant impact on the overall resume time. Suggested-by: Bard Liao <yung-chuan.liao@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210714051349.13064-1-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-07-14 13:13:49 +08:00
soundwire: cadence: add paranoid check on self-clearing bits The Cadence IP exposes a small number of self-clearing bits in the MCP_CONTROL and MCP_CONFIG_UPDATE registers. We currently do not check that those bits are indeed cleared, e.g. during resume operations. That could lead to resuming peripheral devices too early. In addition, if we happen to read these registers, update one of the fields and write the register back, we may be writing stale data that might have been cleared in hardware. These sort of race conditions could lead to e.g. doing a hw_reset twice or stopping a clock that just restarted. There is no clear way of avoiding these potential race conditions other than making sure that these registers fields are cleared before any read-modify-write sequence. If we detect this sort of errors, we only log them since there is no clear recovery possible. The only way out is likely to restart the IP with a suspend/resume cycle. Note that the checks are performed before updating the registers, as well as after the Intel 'sync go' sequence in multi-link mode. That should cover both the start and end of suspend/resume hardware configurations. The Multi-Master mode gates the configuration updates until the 'sync go' signal is asserted, so we only check on init and after the end of the 'sync go' sequence. The duration of the usleep_range() was defined by the GSYNC frequency used in multi-master mode. With a 4kHz frequency, any configuration change might be deferred by up to 250us. Extending the range to 1000-1500us should guarantee that the configuration change is completed without any significant impact on the overall resume time. Suggested-by: Bard Liao <yung-chuan.liao@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210714051349.13064-1-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-07-14 13:13:49 +08:00
soundwire: intel: conditionally exit clock stop mode on system suspend Intel stress tests reported issues with the clock stop mode, specifically when trying to do a system suspend while the link is already pm_runtime suspended. In this case, we need to disable the shim wake, but when the PCI parent device is also pm_runtime suspended the SHIM registers are not accessible. Since this is an invalid corner case, this patch suggests a pm_runtime resume of the entire bus to full power (parent+child devices) before the system suspend so that the shim wake can be disabled. Unlike the suspend operation, the .prepare callbacks are propagated from root device to leaf devices. By adding a .prepare callback at the SoundWire link level, we can double-check the pm_runtime status of the device as well as its parent PCI device. When the problematic configuration is detected, the device is pm_runtime resumed - which by construction also resume its parent. An additional loop is added to resume all child devices. In theory we only need to restart the link, but doing so will also cause the physical devices to synchronize and re-initialize, while their Linux devices remain pm_runtime suspended. It's simpler to make sure the codec devices are fully resumed so that we don't have to deal with zombie states. This additional loop could have been avoided by adding a .prepare callback in SoundWire codec drivers. Functionally this would have been equivalent. The rationale for implementing a loop at the link level is only to reduce the amount of code required to deal at the codec level with an Intel corner case - in other words keep codec drivers independent from Intel platform-specific programming sequences. BugLink: https://github.com/thesofproject/linux/issues/2606 Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com> Link: https://lore.kernel.org/r/20210818024954.16873-4-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2021-08-18 10:49:54 +08:00