From mboxrd@z Thu Jan 1 00:00:00 1970 From: Randy Dunlap Subject: Re: PROBLEM: USB keyboards works only 4 per PC host port Date: Tue, 19 Aug 2008 08:19:36 -0700 Message-ID: <20080819081936.37fef673.rdunlap@xenotime.net> References: <200808080702.24969.aivils@latnet.lv> <200808181642.49489.aivils@latnet.lv> <20080818081432.782d9632.rdunlap@xenotime.net> <200808191527.06945.aivils@latnet.lv> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <200808191527.06945.aivils@latnet.lv> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxconsole-dev-bounces@lists.sourceforge.net Errors-To: linuxconsole-dev-bounces@lists.sourceforge.net To: Aivils Stoss , stern@rowland.harvard.edu Cc: jkosina@suse.cz, lud , linux-kernel@vger.kernel.org, linuxconsole-dev@lists.sourceforge.net, linux-input@vger.kernel.org List-Id: linux-input@vger.kernel.org On Tue, 19 Aug 2008 15:27:06 +0530 Aivils Stoss wrote: > On Monday 18 August 2008 8:44:32 pm Randy Dunlap wrote: > > On Mon, 18 Aug 2008 16:42:49 +0530 Aivils Stoss wrote: > > > On Friday 15 August 2008 7:19:48 am Randy Dunlap wrote: > > > > On Sun, 10 Aug 2008 04:08:37 +0100 Aivils Stoss wrote: > > > > > On Saturday 09 August 2008 11:42:26 am Samuel Thibault wrote: > > > > > > Aivils Stoss, le Fri 08 Aug 2008 07:02:24 +0100, a =E9crit : > > > > > > > I suppose this is Linux kernel bug because i test keyboards u= nder > > > > > > > Windows, which support any schema of cascading of usb hubs. > > > > > > > > > > > > On the very same machine and hubs? > > > > > > > > > > Yes, on same machine. Under Windows i don't have evdev interface, > > > > > checked only how keypress go to console. > > > > > Of course to repeat a try You must have at least 5 keyboards and > > > > > 1 7-port or 2 4-port hubs and kernel 2.6.22 and above. I allways > > > > > got result - 5th, 6th, 7th keyboard does not send events to conso= le > > > > > or evdev. > > > > > > > > [adding linux-usb mailing list] > > > > > > > > Hi, > > > > > > > > I finally got 5 USB keyboards together along with 2 hubs. > > > > I daisy-chained the hubs and connected 1 keyboard to the hub that is > > > > on the notebook computer USB port, then I connected 4 keyboards to = the > > > > second hub. They all worked for me, meaning that I can type on all= of > > > > them and have their characters show up on my console. > > > > > > > > I'm testing with 2.6.7-rc2. > > > > 'usbtree' output of the USB subsystem is attached. > > > > > > Yeah! 2.6.7 is a bit obsolete. At my end 2.6.15 support more than 4 > > > keyboards per PC port , but mess up input when is plugged more than > > > 9 keyboards. 10th is capable to send keypress events, but last pressed > > > key will be repeated until ctrl-c . 10th keyboard disturb an auto rep= eat > > > of all keyboards. > > > > Sorry, my keyboard made a typo. I'm testing with 2.6.27-rc2. > > > > So the problem is now different from your original report, right? > = > No problem is same. Older kernels have another troubles. > 2.6.22-1-mepis-smp > Quite stable. Have oops sometime inside evdev. Support up to 16 = > USB keyboards, where 4 hubs are plugged into PC and 4 keyboards on > each hub. Any hub cascade support only 4 keyboards, where 5th or more > is registered but don't send input events. Oops inside evdev , when > USB keyboard unplugged. No slow down even all USB keyboards does > not work properly. My be this one support more than 16 keyboards, but > i don't have PC USB ports enough. Has the evdev oops been reported and/or fixed? I think that we would prefer to fix that soonish. > 2.6.24-7 > 4 keyboards per port. If plug in 5th tend to total slow down with this on= e: > usb 2-1.1.1: reset low speed USB device using = > uhci_hcd and address 17 > 5th - means 5th keyboard in USB hub's cascade, which is plugged into > single PC USB port. > = > 2.6.26 > 4 keyboards per port. If plug in 5th tend to total slow down. > = > 2.6.27-rc3 > Sorry Randy i cannot repeat Your achievement. This worse of all tested > kernels. I got working 3 USB keyboards, when i plug in 4th, all keyboards, > include PS/2 stop working. Kernel does not hung up. I can reach box > via net. dmesg , /proc/bus/input/devices attached. lsusb hung up. Please try to include full dmesg (kernel boot log) in the future. This was was truncated at the front (early messages). > Please notify me , if i should use 2.6.27-rc2 ! It doesn't seem preferable for you yet. Looks like it could be a problem just to put N low-speed devices on one roo= t hub/port: uhci_hcd 0000:00:1d.1: bandwidth allocation failed: period 8, phase 4, 826 = + 118 us uhci_hcd 0000:00:1d.1: bandwidth allocation failed: period 8, phase 4, 826 = + 118 us uhci_hcd 0000:00:1d.1: bandwidth allocation failed: period 8, phase 4, 826 = + 118 us etc etc. Alan (Stern), could you look at this one, please? > Aivils > = > > > > > > What speed is the host port that the keyboards are connected to? > > Could it be a USB bus bandwidth limitation? (not that any code > > checks for that) > > > > I barely found 5 USB keyboards, so I surely can't test 10 or more. ;) > > I suppose that it will take some USB debug messages to attempt to see > > what is going on... --- ~Randy Linux Plumbers Conference, 17-19 September 2008, Portland, Oregon USA http://linuxplumbersconf.org/ ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great priz= es Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=3D100&url=3D/