linux/drivers/phy/tegra/xusb-tegra186.c

1760 lines
48 KiB

phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: xusb: Use a bitmask for UTMI pad power state tracking The current implementation uses bias_pad_enable as a reference count to manage the shared bias pad for all UTMI PHYs. However, during system suspension with connected USB devices, multiple power-down requests for the UTMI pad result in a mismatch in the reference count, which in turn produces warnings such as: [ 237.762967] WARNING: CPU: 10 PID: 1618 at tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763103] Call trace: [ 237.763104] tegra186_utmi_pad_power_down+0x160/0x170 [ 237.763107] tegra186_utmi_phy_power_off+0x10/0x30 [ 237.763110] phy_power_off+0x48/0x100 [ 237.763113] tegra_xusb_enter_elpg+0x204/0x500 [ 237.763119] tegra_xusb_suspend+0x48/0x140 [ 237.763122] platform_pm_suspend+0x2c/0xb0 [ 237.763125] dpm_run_callback.isra.0+0x20/0xa0 [ 237.763127] __device_suspend+0x118/0x330 [ 237.763129] dpm_suspend+0x10c/0x1f0 [ 237.763130] dpm_suspend_start+0x88/0xb0 [ 237.763132] suspend_devices_and_enter+0x120/0x500 [ 237.763135] pm_suspend+0x1ec/0x270 The root cause was traced back to the dynamic power-down changes introduced in commit a30951d31b25 ("xhci: tegra: USB2 pad power controls"), where the UTMI pad was being powered down without verifying its current state. This unbalanced behavior led to discrepancies in the reference count. To rectify this issue, this patch replaces the single reference counter with a bitmask, renamed to utmi_pad_enabled. Each bit in the mask corresponds to one of the four USB2 PHYs, allowing us to track each pad's enablement status individually. With this change: - The bias pad is powered on only when the mask is clear. - Each UTMI pad is powered on or down based on its corresponding bit in the mask, preventing redundant operations. - The overall power state of the shared bias pad is maintained correctly during suspend/resume cycles. The mutex used to prevent race conditions during UTMI pad enable/disable operations has been moved from the tegra186_utmi_bias_pad_power_on/off functions to the parent functions tegra186_utmi_pad_power_on/down. This change ensures that there are no race conditions when updating the bitmask. Cc: stable@vger.kernel.org Fixes: a30951d31b25 ("xhci: tegra: USB2 pad power controls") Signed-off-by: Wayne Chang <waynec@nvidia.com> Reviewed-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Link: https://lore.kernel.org/r/20250408030905.990474-1-waynec@nvidia.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2025-04-08 11:09:05 +08:00
phy: tegra: Don't use device-managed API to allocate ports The device-managed allocation API doesn't work well with the life-cycle of device objects. Since ports have device objects allocated within, it can lead to situations where these devices need to stay around until after their parent pad controller has been unbound from its driver. The device-managed memory allocated for the port objects will, however, get freed when the pad controller unbinds from the driver. This can cause use-after-free errors down the road. Note that the device is deleted as part of the driver unbind operation, so there isn't much that can be done with it after that point, but the memory still needs to stay around to ensure none of the references are invalidated. One situation where this arises is when a VBUS supply is associated with a USB 2 or 3 port. When that supply is released using regulator_put() an SRCU call will queue the release of the device link connecting the port and the regulator after a grace period. This means that the regulator is going to keep on to the last reference of the port device even after the pad controller driver was unbound (which is when the memory backing the port device is freed). Fix this by allocating port objects using non-device-managed memory. Add release callbacks for these objects so that their memory gets freed when the last reference goes away. This decouples the port devices' lifetime from the "active" lifetime of the pad controller (i.e. the time during which the pad controller driver owns the device). Signed-off-by: Thierry Reding <treding@nvidia.com>
2020-03-19 11:52:13 +01:00
phy: tegra: Don't use device-managed API to allocate ports The device-managed allocation API doesn't work well with the life-cycle of device objects. Since ports have device objects allocated within, it can lead to situations where these devices need to stay around until after their parent pad controller has been unbound from its driver. The device-managed memory allocated for the port objects will, however, get freed when the pad controller unbinds from the driver. This can cause use-after-free errors down the road. Note that the device is deleted as part of the driver unbind operation, so there isn't much that can be done with it after that point, but the memory still needs to stay around to ensure none of the references are invalidated. One situation where this arises is when a VBUS supply is associated with a USB 2 or 3 port. When that supply is released using regulator_put() an SRCU call will queue the release of the device link connecting the port and the regulator after a grace period. This means that the regulator is going to keep on to the last reference of the port device even after the pad controller driver was unbound (which is when the memory backing the port device is freed). Fix this by allocating port objects using non-device-managed memory. Add release callbacks for these objects so that their memory gets freed when the last reference goes away. This decouples the port devices' lifetime from the "active" lifetime of the pad controller (i.e. the time during which the pad controller driver owns the device). Signed-off-by: Thierry Reding <treding@nvidia.com>
2020-03-19 11:52:13 +01:00