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

[Jon Hunter <jonathanh@nvidia.com>]

Hi Greg,

On 18/12/2024 16:21, Jon Hunter wrote:
> 
> 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/


Let me know if you OK to pick up this fix now?

Thanks!
Jon

-- 
nvpublic