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SubjectRe: [PATCH v2 1/2] usb: dwc3: gadget: Bail out in pullup if soft reset timeout happens
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On 3/29/2023 2:50 AM, Thinh Nguyen wrote:
> Hi,
>
> On Tue, Mar 28, 2023, Krishna Kurapati wrote:
>> If the core soft reset timeout happens, avoid setting up event
>> buffers and starting gadget as the writes to these registers
>> may not reflect when in reset and setting the run stop bit
>> can lead the controller to access wrong event buffer address
>> resulting in a crash.
>>
>> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
>> ---
>> drivers/usb/dwc3/gadget.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
>> index 3c63fa97a680..f0472801d9a5 100644
>> --- a/drivers/usb/dwc3/gadget.c
>> +++ b/drivers/usb/dwc3/gadget.c
>> @@ -2620,13 +2620,16 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on)
>> * device-initiated disconnect requires a core soft reset
>> * (DCTL.CSftRst) before enabling the run/stop bit.
>> */
>> - dwc3_core_soft_reset(dwc);
>> + ret = dwc3_core_soft_reset(dwc);
>> + if (ret)
>> + goto done;
>>
>> dwc3_event_buffers_setup(dwc);
>> __dwc3_gadget_start(dwc);
>> ret = dwc3_gadget_run_stop(dwc, true, false);
>> }
>>
>> +done:
>> pm_runtime_put(dwc->dev);
>>
>> return ret;
>> --
>> 2.40.0
>>
>
> I think there's one more place that may needs this check. Can you also
> add this check in __dwc3_set_mode()?

Hi Thinh,

Sure. Will do it.
Will the below be good enough ? Or would it be good to add an error/warn
log there>

kriskura@hu-kriskura-hyd:/local/mnt/workspace/krishna/skales2/skales/kernel$
git diff drivers/usb/
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 476b63618511..8d1d213d1dcd 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -210,7 +210,9 @@ static void __dwc3_set_mode(struct work_struct *work)
}
break;
case DWC3_GCTL_PRTCAP_DEVICE:
- dwc3_core_soft_reset(dwc);
+ ret = dwc3_core_soft_reset(dwc);
+ if (ret)
+ goto out;

dwc3_event_buffers_setup(dwc);

Regards,
Krishna,
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