Re: [PATCH] usb: dwc3: qcom: Add shutdown handler

[Prashanth K <prashanth.k@oss.qualcomm.com>]

On 7/25/2025 2:18 PM, Greg Kroah-Hartman wrote:
> On Fri, Jul 25, 2025 at 11:51:58AM +0530, Prashanth K wrote:
>> Currently during system reboot, SMMU disables its translations
>> while devices like USB may still be actively using DMA buffers.
>> This can lead to NOC errors and system crashes due to invalid
>> memory access.
>>
>> Address this by adding a shutdown callback to dwc3-qcom, which
>> ensures proper teardown of UDC stack and prevents DWC3 controller
>> from accessing memory after SMMU translation is disabled. Reuse
>> the existing remove callback for this purpose.
>>
>> Signed-off-by: Prashanth K <prashanth.k@oss.qualcomm.com>
>> ---
>>  drivers/usb/dwc3/dwc3-qcom.c | 8 ++++++--
>>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> What commit id does this fix?  Or is this just a new feature?
> 
> thanks,
> 
> greg k-h

I didn't Fixes tag because a small dilemma. This patch is rebased on top
of the flattening series, specifically commit 1881a32fe14d ("usb: dwc3:
qcom: Transition to flattened model").
However, I don't think that this commit caused this issue.

Let me know if you want the Fixes tag.

Thanks in advance,
Prashanth K