Re: [PATCH v3] USB: core: Disable LPM only for non-suspended ports

[Jon Hunter <jonathanh@nvidia.com>]

On 06/12/2024 07:48, Kai-Heng Feng wrote:
> There's USB error when tegra board is shutting down:
> [  180.919315] usb 2-3: Failed to set U1 timeout to 0x0,error code -113
> [  180.919995] usb 2-3: Failed to set U1 timeout to 0xa,error code -113
> [  180.920512] usb 2-3: Failed to set U2 timeout to 0x4,error code -113
> [  186.157172] tegra-xusb 3610000.usb: xHCI host controller not responding, assume dead
> [  186.157858] tegra-xusb 3610000.usb: HC died; cleaning up
> [  186.317280] tegra-xusb 3610000.usb: Timeout while waiting for evaluate context command
> 
> The issue is caused by disabling LPM on already suspended ports.
> 
> For USB2 LPM, the LPM is already disabled during port suspend. For USB3
> LPM, port won't transit to U1/U2 when it's already suspended in U3,
> hence disabling LPM is only needed for ports that are not suspended.
> 
> Cc: Wayne Chang <waynec@nvidia.com>
> Cc: stable@vger.kernel.org
> Fixes: d920a2ed8620 ("usb: Disable USB3 LPM at shutdown")
> Signed-off-by: Kai-Heng Feng <kaihengf@nvidia.com>
> ---
> v3:
>   Use udev->port_is_suspended which reflects upstream port status
> 
> v2:
>   Add "Cc: stable@vger.kernel.org"
> 
>   drivers/usb/core/port.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/core/port.c b/drivers/usb/core/port.c
> index e7da2fca11a4..c92fb648a1c4 100644
> --- a/drivers/usb/core/port.c
> +++ b/drivers/usb/core/port.c
> @@ -452,10 +452,11 @@ static int usb_port_runtime_suspend(struct device *dev)
>   static void usb_port_shutdown(struct device *dev)
>   {
>   	struct usb_port *port_dev = to_usb_port(dev);
> +	struct usb_device *udev = port_dev->child;
>   
> -	if (port_dev->child) {
> -		usb_disable_usb2_hardware_lpm(port_dev->child);
> -		usb_unlocked_disable_lpm(port_dev->child);
> +	if (udev && !udev->port_is_suspended) {
> +		usb_disable_usb2_hardware_lpm(udev);
> +		usb_unlocked_disable_lpm(udev);
>   	}
>   }
>   


This resolves the issue I have been seeing [0].

Tested-by: Jon Hunter <jonathanh@nvidia.com>

Thanks!
Jon

[0] 
https://lore.kernel.org/linux-usb/d5e79487-0f99-4ff2-8f49-0c403f1190af@nvidia.com/

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