linux/drivers/firewire/core-card.c

787 lines
23 KiB

firewire: core: use non-reentrant workqueue with rescuer firewire-core manages the following types of work items: fw_card.br_work: - resets the bus on a card and possibly sends a PHY packet before that - does not sleep for long or not at all - is scheduled via fw_schedule_bus_reset() by - firewire-ohci's pci_probe method - firewire-ohci's set_config_rom method, called by kernelspace protocol drivers and userspace drivers which add/remove Configuration ROM descriptors - userspace drivers which use the bus reset ioctl - itself if the last reset happened less than 2 seconds ago fw_card.bm_work: - performs bus management duties - usually does not (but may in corner cases) sleep for long - is scheduled via fw_schedule_bm_work() by - firewire-ohci's self-ID-complete IRQ handler tasklet - firewire-core's fw_device.work instances whenever the root node device was (successfully or unsuccessfully) discovered, refreshed, or rediscovered - itself in case of resource allocation failures or in order to obey the 125ms bus manager arbitration interval fw_device.work: - performs node probe, update, shutdown, revival, removal; including kernel driver probe, update, shutdown and bus reset notification to userspace drivers - usually sleeps moderately long, in corner cases very long - is scheduled by - firewire-ohci's self-ID-complete IRQ handler tasklet via the core's fw_node_event - firewire-ohci's pci_remove method via core's fw_destroy_nodes/ fw_node_event - itself during retries, e.g. while a node is powering up iso_resource.work: - accesses registers at the Isochronous Resource Manager node - usually does not (but may in corner cases) sleep for long - is scheduled via schedule_iso_resource() by - the owning userspace driver at addition and removal of the resource - firewire-core's fw_device.work instances after bus reset - itself in case of resource allocation if necessary to obey the 1000ms reallocation period after bus reset fw_card.br_work instances should not, and instances of the others must not, be executed in parallel by multiple CPUs -- but were not protected against that. Hence allocate a non-reentrant workqueue for them. fw_device.work may be used in the memory reclaim path in case of SBP-2 device updates. Hence we need a workqueue with rescuer and cannot use system_nrt_wq. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Reviewed-by: Tejun Heo <tj@kernel.org>
2010-10-13 13:39:46 +02:00
firewire: core: check for 1394a compliant IRM, fix inaccessibility of Sony camcorder Per IEEE 1394 clause 8.4.2.3, a contender for the IRM role shall check whether the current IRM complies to 1394a-2000 or later. If not force a compliant node (e.g. itself) to become IRM. This was implemented in the older ieee1394 driver but not yet in firewire-core. An older Sony camcorder (Sony DCR-TRV25) which implements 1394-1995 IRM but neither 1394a-2000 IRM nor BM was now found to cause an interoperability bug: - Camcorder becomes root node when plugged in, hence gets IRM role. - firewire-core successfully contends for BM role, proceeds to perform gap count optimization and resets the bus. - Sony camcorder ignores presence of a BM (against the spec, this is a firmware bug), performs its idea of gap count optimization and resets the bus. - Preceding two steps are repeated endlessly, bus never settles, regular I/O is practically impossible. http://thread.gmane.org/gmane.linux.kernel.firewire.user/3913 This is an interoperability regression from the old to the new drivers. Fix it indirectly by adding the 1394a IRM check. The spec suggests three and a half methods to determine 1394a compliance of a remote IRM; we choose the method of testing the Config_ROM.Bus_Info.generation field. This is data that firewire-core should have readily available at this point, i.e. does not require extra I/O. Reported-by: Clemens Ladisch <clemens@ladisch.de> (missing 1394a check) Reported-by: H. S. <hs.samix@gmail.com> (issue with Sony DCR-TRV25) Tested-by: H. S. <hs.samix@gmail.com> Cc: <stable@kernel.org> # .32.x and newer Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-05-30 19:43:52 +02:00
firewire: core: check for 1394a compliant IRM, fix inaccessibility of Sony camcorder Per IEEE 1394 clause 8.4.2.3, a contender for the IRM role shall check whether the current IRM complies to 1394a-2000 or later. If not force a compliant node (e.g. itself) to become IRM. This was implemented in the older ieee1394 driver but not yet in firewire-core. An older Sony camcorder (Sony DCR-TRV25) which implements 1394-1995 IRM but neither 1394a-2000 IRM nor BM was now found to cause an interoperability bug: - Camcorder becomes root node when plugged in, hence gets IRM role. - firewire-core successfully contends for BM role, proceeds to perform gap count optimization and resets the bus. - Sony camcorder ignores presence of a BM (against the spec, this is a firmware bug), performs its idea of gap count optimization and resets the bus. - Preceding two steps are repeated endlessly, bus never settles, regular I/O is practically impossible. http://thread.gmane.org/gmane.linux.kernel.firewire.user/3913 This is an interoperability regression from the old to the new drivers. Fix it indirectly by adding the 1394a IRM check. The spec suggests three and a half methods to determine 1394a compliance of a remote IRM; we choose the method of testing the Config_ROM.Bus_Info.generation field. This is data that firewire-core should have readily available at this point, i.e. does not require extra I/O. Reported-by: Clemens Ladisch <clemens@ladisch.de> (missing 1394a check) Reported-by: H. S. <hs.samix@gmail.com> (issue with Sony DCR-TRV25) Tested-by: H. S. <hs.samix@gmail.com> Cc: <stable@kernel.org> # .32.x and newer Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-05-30 19:43:52 +02:00
firewire: core: check for 1394a compliant IRM, fix inaccessibility of Sony camcorder Per IEEE 1394 clause 8.4.2.3, a contender for the IRM role shall check whether the current IRM complies to 1394a-2000 or later. If not force a compliant node (e.g. itself) to become IRM. This was implemented in the older ieee1394 driver but not yet in firewire-core. An older Sony camcorder (Sony DCR-TRV25) which implements 1394-1995 IRM but neither 1394a-2000 IRM nor BM was now found to cause an interoperability bug: - Camcorder becomes root node when plugged in, hence gets IRM role. - firewire-core successfully contends for BM role, proceeds to perform gap count optimization and resets the bus. - Sony camcorder ignores presence of a BM (against the spec, this is a firmware bug), performs its idea of gap count optimization and resets the bus. - Preceding two steps are repeated endlessly, bus never settles, regular I/O is practically impossible. http://thread.gmane.org/gmane.linux.kernel.firewire.user/3913 This is an interoperability regression from the old to the new drivers. Fix it indirectly by adding the 1394a IRM check. The spec suggests three and a half methods to determine 1394a compliance of a remote IRM; we choose the method of testing the Config_ROM.Bus_Info.generation field. This is data that firewire-core should have readily available at this point, i.e. does not require extra I/O. Reported-by: Clemens Ladisch <clemens@ladisch.de> (missing 1394a check) Reported-by: H. S. <hs.samix@gmail.com> (issue with Sony DCR-TRV25) Tested-by: H. S. <hs.samix@gmail.com> Cc: <stable@kernel.org> # .32.x and newer Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-05-30 19:43:52 +02:00
firewire: core: check for 1394a compliant IRM, fix inaccessibility of Sony camcorder Per IEEE 1394 clause 8.4.2.3, a contender for the IRM role shall check whether the current IRM complies to 1394a-2000 or later. If not force a compliant node (e.g. itself) to become IRM. This was implemented in the older ieee1394 driver but not yet in firewire-core. An older Sony camcorder (Sony DCR-TRV25) which implements 1394-1995 IRM but neither 1394a-2000 IRM nor BM was now found to cause an interoperability bug: - Camcorder becomes root node when plugged in, hence gets IRM role. - firewire-core successfully contends for BM role, proceeds to perform gap count optimization and resets the bus. - Sony camcorder ignores presence of a BM (against the spec, this is a firmware bug), performs its idea of gap count optimization and resets the bus. - Preceding two steps are repeated endlessly, bus never settles, regular I/O is practically impossible. http://thread.gmane.org/gmane.linux.kernel.firewire.user/3913 This is an interoperability regression from the old to the new drivers. Fix it indirectly by adding the 1394a IRM check. The spec suggests three and a half methods to determine 1394a compliance of a remote IRM; we choose the method of testing the Config_ROM.Bus_Info.generation field. This is data that firewire-core should have readily available at this point, i.e. does not require extra I/O. Reported-by: Clemens Ladisch <clemens@ladisch.de> (missing 1394a check) Reported-by: H. S. <hs.samix@gmail.com> (issue with Sony DCR-TRV25) Tested-by: H. S. <hs.samix@gmail.com> Cc: <stable@kernel.org> # .32.x and newer Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-05-30 19:43:52 +02:00
firewire: core: check for 1394a compliant IRM, fix inaccessibility of Sony camcorder Per IEEE 1394 clause 8.4.2.3, a contender for the IRM role shall check whether the current IRM complies to 1394a-2000 or later. If not force a compliant node (e.g. itself) to become IRM. This was implemented in the older ieee1394 driver but not yet in firewire-core. An older Sony camcorder (Sony DCR-TRV25) which implements 1394-1995 IRM but neither 1394a-2000 IRM nor BM was now found to cause an interoperability bug: - Camcorder becomes root node when plugged in, hence gets IRM role. - firewire-core successfully contends for BM role, proceeds to perform gap count optimization and resets the bus. - Sony camcorder ignores presence of a BM (against the spec, this is a firmware bug), performs its idea of gap count optimization and resets the bus. - Preceding two steps are repeated endlessly, bus never settles, regular I/O is practically impossible. http://thread.gmane.org/gmane.linux.kernel.firewire.user/3913 This is an interoperability regression from the old to the new drivers. Fix it indirectly by adding the 1394a IRM check. The spec suggests three and a half methods to determine 1394a compliance of a remote IRM; we choose the method of testing the Config_ROM.Bus_Info.generation field. This is data that firewire-core should have readily available at this point, i.e. does not require extra I/O. Reported-by: Clemens Ladisch <clemens@ladisch.de> (missing 1394a check) Reported-by: H. S. <hs.samix@gmail.com> (issue with Sony DCR-TRV25) Tested-by: H. S. <hs.samix@gmail.com> Cc: <stable@kernel.org> # .32.x and newer Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-05-30 19:43:52 +02:00
firewire: core: check for 1394a compliant IRM, fix inaccessibility of Sony camcorder Per IEEE 1394 clause 8.4.2.3, a contender for the IRM role shall check whether the current IRM complies to 1394a-2000 or later. If not force a compliant node (e.g. itself) to become IRM. This was implemented in the older ieee1394 driver but not yet in firewire-core. An older Sony camcorder (Sony DCR-TRV25) which implements 1394-1995 IRM but neither 1394a-2000 IRM nor BM was now found to cause an interoperability bug: - Camcorder becomes root node when plugged in, hence gets IRM role. - firewire-core successfully contends for BM role, proceeds to perform gap count optimization and resets the bus. - Sony camcorder ignores presence of a BM (against the spec, this is a firmware bug), performs its idea of gap count optimization and resets the bus. - Preceding two steps are repeated endlessly, bus never settles, regular I/O is practically impossible. http://thread.gmane.org/gmane.linux.kernel.firewire.user/3913 This is an interoperability regression from the old to the new drivers. Fix it indirectly by adding the 1394a IRM check. The spec suggests three and a half methods to determine 1394a compliance of a remote IRM; we choose the method of testing the Config_ROM.Bus_Info.generation field. This is data that firewire-core should have readily available at this point, i.e. does not require extra I/O. Reported-by: Clemens Ladisch <clemens@ladisch.de> (missing 1394a check) Reported-by: H. S. <hs.samix@gmail.com> (issue with Sony DCR-TRV25) Tested-by: H. S. <hs.samix@gmail.com> Cc: <stable@kernel.org> # .32.x and newer Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-05-30 19:43:52 +02:00
firewire: core: check for 1394a compliant IRM, fix inaccessibility of Sony camcorder Per IEEE 1394 clause 8.4.2.3, a contender for the IRM role shall check whether the current IRM complies to 1394a-2000 or later. If not force a compliant node (e.g. itself) to become IRM. This was implemented in the older ieee1394 driver but not yet in firewire-core. An older Sony camcorder (Sony DCR-TRV25) which implements 1394-1995 IRM but neither 1394a-2000 IRM nor BM was now found to cause an interoperability bug: - Camcorder becomes root node when plugged in, hence gets IRM role. - firewire-core successfully contends for BM role, proceeds to perform gap count optimization and resets the bus. - Sony camcorder ignores presence of a BM (against the spec, this is a firmware bug), performs its idea of gap count optimization and resets the bus. - Preceding two steps are repeated endlessly, bus never settles, regular I/O is practically impossible. http://thread.gmane.org/gmane.linux.kernel.firewire.user/3913 This is an interoperability regression from the old to the new drivers. Fix it indirectly by adding the 1394a IRM check. The spec suggests three and a half methods to determine 1394a compliance of a remote IRM; we choose the method of testing the Config_ROM.Bus_Info.generation field. This is data that firewire-core should have readily available at this point, i.e. does not require extra I/O. Reported-by: Clemens Ladisch <clemens@ladisch.de> (missing 1394a check) Reported-by: H. S. <hs.samix@gmail.com> (issue with Sony DCR-TRV25) Tested-by: H. S. <hs.samix@gmail.com> Cc: <stable@kernel.org> # .32.x and newer Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-05-30 19:43:52 +02:00
firewire: core: send bus reset promptly on gap count error If we are bus manager and the bus has inconsistent gap counts, send a bus reset immediately instead of trying to read the root node's config ROM first. Otherwise, we could spend a lot of time trying to read the config ROM but never succeeding. This eliminates a 50+ second delay before the FireWire bus is usable after a newly connected device is powered on in certain circumstances. The delay occurs if a gap count inconsistency occurs, we are not the root node, and we become bus manager. One scenario that causes this is with a TI XIO2213B OHCI, the first time a Sony DSR-25 is powered on after being connected to the FireWire cable. In this configuration, the Linux box will not receive the initial PHY configuration packet sent by the DSR-25 as IRM, resulting in the DSR-25 having a gap count of 44 while the Linux box has a gap count of 63. FireWire devices have a gap count parameter, which is set to 63 on power-up and can be changed with a PHY configuration packet. This determines the duration of the subaction and arbitration gaps. For reliable communication, all nodes on a FireWire bus must have the same gap count. A node may have zero or more of the following roles: root node, bus manager (BM), isochronous resource manager (IRM), and cycle master. Unless a root node was forced with a PHY configuration packet, any node might become root node after a bus reset. Only the root node can become cycle master. If the root node is not cycle master capable, the BM or IRM should force a change of root node. After a bus reset, each node sends a self-ID packet, which contains its current gap count. A single bus reset does not change the gap count, but two bus resets in a row will set the gap count to 63. Because a consistent gap count is required for reliable communication, IEEE 1394a-2000 requires that the bus manager generate a bus reset if it detects that the gap count is inconsistent. When the gap count is inconsistent, build_tree() will notice this after the self identification process. It will set card->gap_count to the invalid value 0. If we become bus master, this will force bm_work() to send a bus reset when it performs gap count optimization. After a bus reset, there is no bus manager. We will almost always try to become bus manager. Once we become bus manager, we will first determine whether the root node is cycle master capable. Then, we will determine if the gap count should be changed. If either the root node or the gap count should be changed, we will generate a bus reset. To determine if the root node is cycle master capable, we read its configuration ROM. bm_work() will wait until we have finished trying to read the configuration ROM. However, an inconsistent gap count can make this take a long time. read_config_rom() will read the first few quadlets from the config ROM. Due to the gap count inconsistency, eventually one of the reads will time out. When read_config_rom() fails, fw_device_init() calls it again until MAX_RETRIES is reached. This takes 50+ seconds. Once we give up trying to read the configuration ROM, bm_work() will wake up, assume that the root node is not cycle master capable, and do a bus reset. Hopefully, this will resolve the gap count inconsistency. This change makes bm_work() check for an inconsistent gap count before waiting for the root node's configuration ROM. If the gap count is inconsistent, bm_work() will immediately do a bus reset. This eliminates the 50+ second delay and rapidly brings the bus to a working state. I considered that if the gap count is inconsistent, a PHY configuration packet might not be successful, so it could be desirable to skip the PHY configuration packet before the bus reset in this case. However, IEEE 1394a-2000 and IEEE 1394-2008 say that the bus manager may transmit a PHY configuration packet before a bus reset when correcting a gap count error. Since the standard endorses this, I decided it's safe to retain the PHY configuration packet transmission. Normally, after a topology change, we will reset the bus a maximum of 5 times to change the root node and perform gap count optimization. However, if there is a gap count inconsistency, we must always generate a bus reset. Otherwise the gap count inconsistency will persist and communication will be unreliable. For that reason, if there is a gap count inconstency, we generate a bus reset even if we already reached the 5 reset limit. Signed-off-by: Adam Goldman <adamg@pobox.com> Reference: https://sourceforge.net/p/linux1394/mailman/message/58727806/ Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
2024-02-07 08:01:17 +09:00
firewire: Add dummy read_csr/write_csr functions (Hector Martin wrote) This fixes segfaults when a card gets yanked off of the PCIe bus while busy, e.g. with a userspace app trying to get the cycle time: [8638860.994310] Call Trace: [8638860.994313] ioctl_get_cycle_timer2+0x4f/0xd0 [firewire_core] [8638860.994323] fw_device_op_ioctl+0xae/0x150 [firewire_core] [8638860.994328] __x64_sys_ioctl+0x7d/0xb0 [8638860.994332] do_syscall_64+0x45/0x80 [8638860.994337] entry_SYSCALL_64_after_hwframe+0x44/0xae (Takashi Sakamoto wrote) As long as reading commit 20802224298c ("firewire: core: add forgotten dummy driver methods, remove unused ones"), three functions are not implemeted in dummy driver for reason; .read_csr, .write_csr, and .set_config_rom. In core of Linux FireWire subsystem, the callback of .set_config_rom is under acquisition of mutual exclusive for local list of card. The acquision is also done in process for removal of card, therefore it's safe for missing implementation of .set_config_rom. On the other hand, no lock primitive accompanies any call of .read_csr and .write_csr. For userspace client, check of node shutdown is done in the beginning of dispatch of ioctl request, while node shifts to shutdown state in workqueue context enough after card shifts to dummy driver. It's probable that these two functions are called for the dummy driver by the code of userspace client. In-kernel unit driver has similar situation. It's better to add implementation of the two functions for dummy driver. Signed-off-by: Hector Martin <marcan@marcan.st> Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20220405072221.226217-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-04-05 16:22:19 +09:00
firewire: Add dummy read_csr/write_csr functions (Hector Martin wrote) This fixes segfaults when a card gets yanked off of the PCIe bus while busy, e.g. with a userspace app trying to get the cycle time: [8638860.994310] Call Trace: [8638860.994313] ioctl_get_cycle_timer2+0x4f/0xd0 [firewire_core] [8638860.994323] fw_device_op_ioctl+0xae/0x150 [firewire_core] [8638860.994328] __x64_sys_ioctl+0x7d/0xb0 [8638860.994332] do_syscall_64+0x45/0x80 [8638860.994337] entry_SYSCALL_64_after_hwframe+0x44/0xae (Takashi Sakamoto wrote) As long as reading commit 20802224298c ("firewire: core: add forgotten dummy driver methods, remove unused ones"), three functions are not implemeted in dummy driver for reason; .read_csr, .write_csr, and .set_config_rom. In core of Linux FireWire subsystem, the callback of .set_config_rom is under acquisition of mutual exclusive for local list of card. The acquision is also done in process for removal of card, therefore it's safe for missing implementation of .set_config_rom. On the other hand, no lock primitive accompanies any call of .read_csr and .write_csr. For userspace client, check of node shutdown is done in the beginning of dispatch of ioctl request, while node shifts to shutdown state in workqueue context enough after card shifts to dummy driver. It's probable that these two functions are called for the dummy driver by the code of userspace client. In-kernel unit driver has similar situation. It's better to add implementation of the two functions for dummy driver. Signed-off-by: Hector Martin <marcan@marcan.st> Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Link: https://lore.kernel.org/r/20220405072221.226217-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai <tiwai@suse.de>
2022-04-05 16:22:19 +09:00