6.1-stable review patch. If anyone has any objections, please let me know.
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From: Jim Lin jilin@nvidia.com
commit 732f35cf8bdfece582f6e4a9c659119036577308 upstream.
When a USB device is connected to the OTG port, the tegra_xhci_id_work() routine transitions the PHY to host mode and calls xhci_hub_control() with the SetPortFeature command to enable port power.
In certain cases, the XHCI controller may be in a low-power state when this operation occurs. If xhci_hub_control() is invoked while the controller is suspended, the PORTSC register may return 0xFFFFFFFF, indicating a read failure. This causes xhci_hc_died() to be triggered, leading to host controller shutdown.
Example backtrace: [ 105.445736] Workqueue: events tegra_xhci_id_work [ 105.445747] dump_backtrace+0x0/0x1e8 [ 105.445759] xhci_hc_died.part.48+0x40/0x270 [ 105.445769] tegra_xhci_set_port_power+0xc0/0x240 [ 105.445774] tegra_xhci_id_work+0x130/0x240
To prevent this, ensure the controller is fully resumed before interacting with hardware registers by calling pm_runtime_get_sync() prior to the host mode transition and xhci_hub_control().
Fixes: f836e7843036 ("usb: xhci-tegra: Add OTG support") Cc: stable stable@kernel.org Signed-off-by: Jim Lin jilin@nvidia.com Signed-off-by: Wayne Chang waynec@nvidia.com Link: https://lore.kernel.org/r/20250422114001.126367-1-waynec@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/host/xhci-tegra.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/drivers/usb/host/xhci-tegra.c +++ b/drivers/usb/host/xhci-tegra.c @@ -1228,6 +1228,7 @@ static void tegra_xhci_id_work(struct wo tegra->otg_usb3_port = tegra_xusb_padctl_get_usb3_companion(tegra->padctl, tegra->otg_usb2_port);
+ pm_runtime_get_sync(tegra->dev); if (tegra->host_mode) { /* switch to host mode */ if (tegra->otg_usb3_port >= 0) { @@ -1257,6 +1258,7 @@ static void tegra_xhci_id_work(struct wo }
tegra_xhci_set_port_power(tegra, true, true); + pm_runtime_mark_last_busy(tegra->dev);
} else { if (tegra->otg_usb3_port >= 0) @@ -1264,6 +1266,7 @@ static void tegra_xhci_id_work(struct wo
tegra_xhci_set_port_power(tegra, true, false); } + pm_runtime_put_autosuspend(tegra->dev); }
#if IS_ENABLED(CONFIG_PM) || IS_ENABLED(CONFIG_PM_SLEEP)