On 3/30/2023 5:40 AM, Thinh Nguyen wrote:
On Wed, Mar 29, 2023, Krishna Kurapati PSSNV wrote:
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@xxxxxxxxxxx>
---
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>
There's already a warning message in dwc3_core_soft_reset() if it fails.
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);
If soft-reset failed, the controller is in a bad state. We should not
perform any further operation until the next hard reset. We should flag
the controller as dead. I don't think we have the equivalent of the
host's HCD_FLAG_DEAD. It may require some work in the UDC core. Perhaps
we can flag within dwc3 for now and prevent any further operation for a
simpler fix.
Hi Thinh,
Are you referring that if __dwc3_set_mode failed with core soft reset
timing out, the caller i.e., dwc3_set_mode who queues the work need to
know that the operation actually failed. So we can add a flag to
indicate that gadget is dead and the caller of dwc3_set_mode can check
the flag to see if the operation is successful or not.
Or am I misunderstanding your comment ?
Regards,
Krishna,
