> On Tue, May 24, 2016 at 03:53:53PM +0800, changbin.du@xxxxxxxxx wrote: > > From: "Du, Changbin" <changbin.du@xxxxxxxxx> > > > > Add debugobject support to track the life time of struct urb. > > This feature help us detect violation of urb operations by > > generating a warning message from debugobject core. And we fix > > the possible issues at runtime to avoid oops if we can. > > > > I have done some tests with some class drivers, no violation > > found in them which is good. Expect this feature can be used > > for debugging future problems. > > > > Signed-off-by: Du, Changbin <changbin.du@xxxxxxxxx> > > I agree with Alan, what use is this code? Existing drivers all work > properly because the reference counting of urbs is already present, why > add duplicate counters? That actually leads to bugs. I don't see the > need for this code, please explain it better if you wish for it to be > accepted. What has it found/fixed that we have not found yet? What > does it allow you to do that you can't do today with the existing code? > > thanks, > > greg k-h > I agree with you two now after checking all urb code. I am sorry to disturb you. I did have an object lifetime issue, but it is of usb_request. I expect the cause is usb_request is freed but still pending in udc core. Then I cannot reproduce it, I even cannot know which function driver the usb_request came from. I originally want to use debugojects to debug that issue, then I though this can also help urb debugging. Obviously I am wrong. As you said reference counting of urbs is already present. :) I may add debugojects for device mode usb_request farther. Sometimes it helps. Thank you, Du, Changbin -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
