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usb: host: tegra: Prevent host controller crash when OTG port is used

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commit 732f35cf8b 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: f836e78430 ("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>
This commit is contained in:
Jim Lin
2025-04-22 19:40:01 +08:00
committed by Greg Kroah-Hartman
parent 9b09b99a95
commit 2d44ee69e6
1 changed files with 3 additions and 0 deletions
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drivers/usb/host/xhci-tegra.c
+3
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@@ -1363,6 +1363,7 @@ static void tegra_xhci_id_work(struct work_struct *work)
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) {
@@ -1392,6 +1393,7 @@ static void tegra_xhci_id_work(struct work_struct *work)
}
tegra_xhci_set_port_power(tegra, true, true);
pm_runtime_mark_last_busy(tegra->dev);
} else {
if (tegra->otg_usb3_port >= 0)
@@ -1399,6 +1401,7 @@ static void tegra_xhci_id_work(struct work_struct *work)
tegra_xhci_set_port_power(tegra, true, false);
}
pm_runtime_put_autosuspend(tegra->dev);
}
#if IS_ENABLED(CONFIG_PM) || IS_ENABLED(CONFIG_PM_SLEEP)