Em Wednesday 23 April 2008 00:01:14 Herton Ronaldo Krzesinski escreveu: > Em Monday 21 April 2008 18:14:52 Laurent Pinchart escreveu: > > Hi everybody, > > > > Alan Stern was kind enough to write a fix a few weeks ago for a video > > streaming issue that some of you encountered. > > > > In order to get the fix included in 2.6.26, David Brownell would like to > > know if the Linux UVC driver still suffers from the problem when used > > with 2.6.25 *without* the patch. > > > > Could you please be kind enough to test 2.6.25 and report results ? > > I was testing today with a stock 2.6.25 without the patch and got no > problems. So may be another thing fixed it. If I encounter any problem I'll > report.
Hmm, I got the same problem now with stock 2.6.25. I discovered that the problem is only reproducible when you lower UVC_MAX_ISO_PACKETS in the sources, at least here. I was trying to avoid page allocation failures in another machine lowering from 40 to 8 (after reading http://article.gmane.org/gmane.linux.drivers.uvc.devel/1956), I didn't had time to investigate more so was forgotten: uvcvideo: device USB2.0 Camera requested null bandwidth, defaulting to lowest. kopete: page allocation failure. order:5, mode:0x0 Pid: 6996, comm: kopete Not tainted 2.6.24.4-desktop-2mdvoem #1 [<c010645a>] show_trace_log_lvl+0x1a/0x30 [<c0106ec2>] show_trace+0x12/0x20 [<c010794c>] dump_stack+0x6c/0x80 [<c016e5a8>] __alloc_pages+0x278/0x360 [<c016e6df>] __get_free_pages+0x4f/0x60 [<c010a25a>] dma_alloc_coherent+0xba/0x110 [<ccdd7a17>] hcd_buffer_alloc+0x47/0x80 [usbcore] [<ccdcd335>] usb_buffer_alloc+0x25/0x30 [usbcore] [<ccf59bf8>] uvc_init_video+0x158/0x3b0 [uvcvideo] [<ccf59e9a>] uvc_video_enable+0x4a/0x50 [uvcvideo] [<ccf59229>] uvc_v4l2_do_ioctl+0x999/0xfb0 [uvcvideo] [<ccf40283>] video_usercopy+0xc3/0x230 [videodev] [<ccf58263>] uvc_v4l2_ioctl+0x43/0x50 [uvcvideo] [<c019a578>] do_ioctl+0x88/0xa0 [<c019a7af>] vfs_ioctl+0x21f/0x2a0 [<c019a883>] sys_ioctl+0x53/0x70 [<c010532e>] sysenter_past_esp+0x6b/0xa1 ======================= Mem-info: DMA per-cpu: CPU 0: Hot: hi: 0, btch: 1 usd: 0 Cold: hi: 0, btch: 1 usd: 0 CPU 1: Hot: hi: 0, btch: 1 usd: 0 Cold: hi: 0, btch: 1 usd: 0 Normal per-cpu: CPU 0: Hot: hi: 42, btch: 7 usd: 33 Cold: hi: 14, btch: 3 usd: 13 CPU 1: Hot: hi: 42, btch: 7 usd: 40 Cold: hi: 14, btch: 3 usd: 12 Active:30836 inactive:8955 dirty:0 writeback:0 unstable:0 free:528 slab:3006 mapped:12950 pagetables:371 bounce:0 DMA free:836kB min:144kB low:180kB high:216kB active:9980kB inactive:1260kB present:16256kB pages_scanned:65 all_unreclaimable? no lowmem_reserve[]: 0 173 173 173 Normal free:1276kB min:1608kB low:2008kB high:2412kB active:113364kB inactive:34560kB present:177292kB pages_scanned:0 all_unreclaimable? no lowmem_reserve[]: 0 0 0 0 DMA: 9*4kB 0*8kB 1*16kB 1*32kB 0*64kB 0*128kB 1*256kB 1*512kB 0*1024kB 0*2048kB 0*4096kB = 852kB Normal: 30*4kB 4*8kB 0*16kB 0*32kB 0*64kB 1*128kB 0*256kB 0*512kB 1*1024kB 0*2048kB 0*4096kB = 1304kB Swap cache: add 0, delete 0, find 0/0, race 0+0 Free swap = 1084348kB Total swap = 1084348kB Free swap: 1084348kB 48768 pages of RAM 0 pages of HIGHMEM 1454 reserved pages 58649 pages shared 0 pages swap cached 0 pages dirty 0 pages writeback 12950 pages mapped 3006 pages slab 371 pages pagetableS Without lowering UVC_MAX_ISO_PACKETS I get the above in one machine (it has indeed not much main memory, it's a notebook where free reports 184MB, main memory is shared with onboard video it seems). But recently I saw streaming issues after lowering it in another webcam, so I'm not using this anymore for every machine, then I didn't catch too the -45 errors anymore, now I finally discovered what was happening. So may be we have two bugs here then: - Memory allocation in uvcvideo doesn't work for all cases, urb allocation should be revisited or is it ok? - -45 errors are hidden and only reproducible in some hardware or when lowering UVC_MAX_ISO_PACKETS with some hardware combination (here only one machine showed -45 errors with UVC_MAX_ISO_PACKETS lowered until now). > > > Best regards, > > > > Laurent Pinchart > > > > ---------- Forwarded Message ---------- > > > > Subject: Re: ehci-hcd issue with webcam / uvcvideo driver > > Date: Monday 21 April 2008 > > From: Alan Stern <[EMAIL PROTECTED]> > > To: Laurent Pinchart <[EMAIL PROTECTED]> > > > > On Mon, 21 Apr 2008, Laurent Pinchart wrote: > > > > Below is an updated version of the patch. If you can, replace the > > > > earlier version with this one and give it some good stress testing. > > > > If everything works okay, I'll submit it for inclusion in the > > > > official kernel. > > > > > > I've received several reports from people who tested your patch with > > > the Linux UVC driver. They were all positive, the patch fixed their > > > problem and introduced no regression they noticed. Could the patch be > > > scheduled for 2.6.26 ? > > > > Dave had some questions, in particular, whether your testers still > > encounter problems when running 2.6.25 without the patch. It would be > > nice to know the answer, either way. > > > > (IMO the patch ought to be merged even if the problems are no longer > > present, because what it does is basically correct. There may be a > > detail or two I missed -- it always helps to have someone else review > > changes like this -- but on the whole the idea is right.) > > > > For reference, the current version of the patch is below. > > > > Alan Stern > > -- > []'s > Herton -- []'s Herton _______________________________________________ Linux-uvc-devel mailing list [email protected] https://lists.berlios.de/mailman/listinfo/linux-uvc-devel
