]> www.infradead.org Git - users/jedix/linux-maple.git/commit
usb: host: tegra: Prevent host controller crash when OTG port is used
authorJim Lin <jilin@nvidia.com>
Tue, 22 Apr 2025 11:40:01 +0000 (19:40 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 1 May 2025 15:37:25 +0000 (17:37 +0200)
commit732f35cf8bdfece582f6e4a9c659119036577308
tree8f506f102625663b9cbd174ead7323811b7c2233
parent241e2ce88e5a494be7a5d44c0697592f1632fbee
usb: host: tegra: Prevent host controller crash when OTG port is used

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