On Thu, 19 Feb 2009, morimoto.kuninori@xxxxxxxxxxx wrote: > > Dear Guennadi > > > No, sorry, this is not the test I meant. "-c" doesn't really stress the > > path we need. You really have to execute capture_example multiple times > > completely. The race we're trying to catch happens on STREAMOFF, and for > > that you have to run the example completely through. So, I would suggest > > something like > > > > for (( i=0; i<100; i++ )); do capture_example -d /dev/videoX -f -c 4; done > > wow !! > sorry miss understanding. > > OK. I re-tried test with your script (300 times). > > sh_mobile_ceu_camera didn't crashe with > and without Magnus patch. > > MigoR + ov772x + capture_example > MigoR + tw9910 + capture_example (VUYU fix) > AP325 + ov772x + capture_example Hm, ok, maybe I can ask you about one more test, if you don't mind. The thing is, you only see the problem, if after the ->active buffer has been freed in free_buffer(), your DMA engine continues writing to the freed memory, but you only notice this, if some other driver manages to grab and use it in this time, then its data is going to be overwritten. To actually see, if the race occurs, please do diff -u a/drivers/media/video/sh_mobile_ceu_camera.c b/drivers/media/video/sh_mobile_ceu_camera.c --- a/drivers/media/video/sh_mobile_ceu_camera.c +++ b/drivers/media/video/sh_mobile_ceu_camera.c @@ -326,6 +326,7 @@ spin_lock_irqsave(&pcdev->lock, flags); vb = pcdev->active; + WARN_ON(vb->state == VIDEOBUF_NEEDS_INIT); list_del_init(&vb->queue); if (!list_empty(&pcdev->capture)) Also, I think, even better than restarting capture-example completely would be to edit capture-example.c and put a loop around init_device(); start_capturing(); mainloop(); stop_capturing(); uninit_device(); or maybe even only start_capturing(); mainloop(); stop_capturing(); Best would be to first try all three loops without the patch from Magnus and see if any of them triggers. And use a larger frame (maximum that your sensor can deliver) to give the DMA engine more time per frame. Thanks Guennadi --- Guennadi Liakhovetski, Ph.D. Freelance Open-Source Software Developer -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
