On Thu, May 29, 2014 at 10:50:03AM -0400, Alan Stern wrote: > On Thu, 29 May 2014, Huang Rui wrote: > > > Currently, in usb_sg_wait routine there isn't a timeout on waiting for > > completion signal. When using TEST 5 -> 8 at usbtest module to verify > > a new device controller with gadget zero, it would be hang on this > > phase and this routine waits forever. > > Why did it hang? That's the real problem; you should fix that instead > of adding a timeout. > Right, it might be a HW issue and still under analysis. > > So it should add a timeout about > > 10s to export a TIMEOUT error to return. > > What makes you think 10 seconds is a good timeout value? > This value is rough estimate, and can be changed. > Sorry, this is not acceptable. Any timeout value you specify has to > work for _all_ places that call this routine. 10 minutes might be > okay. > But as a developer's view, when I run the tests, it should be better to report a error even though it fails. But in some specail error cases, usbtest TEST 5 -> 8 which used usb_sg_wait might wait forever and the test is unable to stop. I think it is still not expected, right? So do you have any idea to resolve this issue to make the usbtest report the error codes and complete normally? Thanks, Rui -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html