On Sunday 25 October 2009 13:17:11 Hans de Goede wrote: > Hi, > > On 10/22/2009 09:40 AM, Alexey Fisher wrote: > > Hi Laurent, > > thank you for the answer, i thought - no body care. :) > > > > Am Donnerstag, den 22.10.2009, 01:55 +0200 schrieb Laurent Pinchart: > >> Hi Alexey, > >> > >> On Thursday 15 October 2009 21:00:59 Alexey Fisher wrote: > >>> I did some simple dirty hack, it prevent webcam from being killed by > >>> cheese. On other site it make cheese work too. > >>> Like Paulo said, the camera is slow and it need more time to make > >>> thirst start, some time it need 8 seconds on second start it need about > >>> 2 seconds. If we call STREAMOFF before we get EOF, the camera will die. > >> > >> Which EOF are you talking about here ? The UVC bit in the video packets > >> header ? How have you tested that ? > > > > I used "uvcvideo trace=255" and cheese. > > I talking about "uvc_v4l2_ioctl(VIDIOC_STREAMON)", "Frame complete (EOF > > found)" and "uvc_v4l2_ioctl(VIDIOC_STREAMOFF)". > > > >>> IMHO, the driver should decide if camera ready or not. The easiest way > >>> is, to add SLOWSTART quirk. Correct way probobly will be to check if > >>> camera ready or not. > >>> Any ideas how to make it? Or any other ideas? > >>> > >>> I know, cheese use some bruteforce way to get settings, but the bug in > >>> cheese make the bug in uvcvideo easy to reproduce. > >> > >> It's not a bug in uvcvideo but a bug in the camera. Have you been to > >> isolate exactly which sequence of ioctls issued by Cheese make the > >> camera crash ? I'd like more information about that. > > > > I made dmesg of two situations, webcam work and don't work. > > cheese celling two times "uvc_v4l2_ioctl(VIDIOC_STREAMON)", thirst one > > to get the settings and second time to start the record. Between thirst > > and second pass the time out seems to be too short (even it is 10 > > seconds). > > This is not an issue with the camera, nor with the driver, but an issue > with cheese. In order to not wait for ever when probing devices which for > some reason won't stream, cheese wait a maximum of 3 seconds before the > stream to start, so if the camera is this slow to start, then cheese will > most likely have given up before the cam has started.
If the camera crashes when it receives valid requests in some sequence it's a camera bug. And that means I'll have to find a software workaround :-S -- Regards, Laurent Pinchart _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
