Mauro, thanks for answering, On Thu, Jul 28, 2011 at 10:45:29AM -0300, Mauro Carvalho Chehab wrote: > Em 28-07-2011 08:42, Kirill Smelkov escreveu: > > On Wed, Jul 27, 2011 at 09:42:08PM +0200, Mauro Carvalho Chehab wrote: > >> This is an automatic generated email to let you know that the following patch were queued at the > >> http://git.linuxtv.org/media_tree.git tree: > >> > >> Subject: [media] uvcvideo: Add FIX_BANDWIDTH quirk to HP Webcam on HP Mini 5103 netbook > >> Author: Kirill Smelkov <kirr@xxxxxxxxxx> > >> Date: Fri Jul 22 11:47:22 2011 -0300 > > > > Thanks > > > > > >> The camera there identifies itself as being manufactured by Cheng Uei > >> Precision Industry Co., Ltd (Foxlink), and product is titled as "HP > >> Webcam [2 MP Fixed]". > >> > >> I was trying to get 2 USB video capture devices to work simultaneously, > >> and noticed that the above mentioned webcam always requires packet size > >> = 3072 bytes per micro frame (~= 23.4 MB/s isoc bandwidth), which is far > >> more than enough to get standard NTSC 640x480x2x30 = ~17.6 MB/s isoc > >> bandwidth. > >> > >> As there are alt interfaces with smaller MxPS > >> > >> T: Bus=01 Lev=01 Prnt=01 Port=03 Cnt=01 Dev#= 2 Spd=480 MxCh= 0 > >> D: Ver= 2.00 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs= 1 > >> P: Vendor=05c8 ProdID=0403 Rev= 1.06 > >> S: Manufacturer=Foxlink > >> S: Product=HP Webcam [2 MP Fixed] > >> S: SerialNumber=200909240102 > >> C:* #Ifs= 2 Cfg#= 1 Atr=80 MxPwr=500mA > >> A: FirstIf#= 0 IfCount= 2 Cls=0e(video) Sub=03 Prot=00 > >> I:* If#= 0 Alt= 0 #EPs= 1 Cls=0e(video) Sub=01 Prot=00 Driver=uvcvideo > >> E: Ad=83(I) Atr=03(Int.) MxPS= 16 Ivl=4ms > >> I:* If#= 1 Alt= 0 #EPs= 0 Cls=0e(video) Sub=02 Prot=00 Driver=uvcvideo > >> I: If#= 1 Alt= 1 #EPs= 1 Cls=0e(video) Sub=02 Prot=00 Driver=uvcvideo > >> E: Ad=81(I) Atr=05(Isoc) MxPS= 128 Ivl=125us > >> I: If#= 1 Alt= 2 #EPs= 1 Cls=0e(video) Sub=02 Prot=00 Driver=uvcvideo > >> E: Ad=81(I) Atr=05(Isoc) MxPS= 512 Ivl=125us > >> I: If#= 1 Alt= 3 #EPs= 1 Cls=0e(video) Sub=02 Prot=00 Driver=uvcvideo > >> E: Ad=81(I) Atr=05(Isoc) MxPS=1024 Ivl=125us > >> I: If#= 1 Alt= 4 #EPs= 1 Cls=0e(video) Sub=02 Prot=00 Driver=uvcvideo > >> E: Ad=81(I) Atr=05(Isoc) MxPS=1536 Ivl=125us > >> I: If#= 1 Alt= 5 #EPs= 1 Cls=0e(video) Sub=02 Prot=00 Driver=uvcvideo > >> E: Ad=81(I) Atr=05(Isoc) MxPS=2048 Ivl=125us > >> I: If#= 1 Alt= 6 #EPs= 1 Cls=0e(video) Sub=02 Prot=00 Driver=uvcvideo > >> E: Ad=81(I) Atr=05(Isoc) MxPS=2688 Ivl=125us > >> I: If#= 1 Alt= 7 #EPs= 1 Cls=0e(video) Sub=02 Prot=00 Driver=uvcvideo > >> E: Ad=81(I) Atr=05(Isoc) MxPS=3072 Ivl=125us > >> > >> UVC_QUIRK_FIX_BANDWIDTH helps here and NTSC video can be served with > >> MxPS=2688 i.e. 20.5 MB/s isoc bandwidth. > >> > >> In terms of microframe time allocation, before the quirk NTSC video > >> required 60 usecs / microframe and 53 usecs / microframe after. > >> > >> Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> > >> Signed-off-by: Kirill Smelkov <kirr@xxxxxxxxxx> > >> Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> > > > > > > May I ask, why you removed the reference to cc62a7eb? Original patch > > description contained the following paragraph just before sob > > > > Now with tweaked ehci-hcd to allow up to 90% isoc bandwidth (cc62a7eb > > "USB: EHCI: Allow users to override 80% max periodic bandwidth") I can > > capture two video sources -- PAL 720x576 YUV422 @25fps + NTSC 640x480 > > YUV422 @30fps simultaneously. Hooray! > > > > > > which was removed on applying. > > For a few reasons: > 1) I was not sure if the changeset reference was not changed when And it was not changed, because when I referenced it, it was already in Greg's usb tree, and Linus pulls from Greg and Greg does not destroy history as far as I can tell... > merged upstream, and I was too lazy^Wbusy to double check ;) It's just doing `git log linus/master | grep cc62a7eb`. Compared or less time to editing... > 2) Reducing the amount of bandwidth used is good, even without trying to use > two webcams; > 3) The bandwidth override patch is independent of this one. Yes, but coupled, and also they were motivated by each other. Could we please merge my comment back, or is it too late? Thanks, Kirill -- 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
