From mboxrd@z Thu Jan 1 00:00:00 1970 From: "=?ISO-8859-15?Q?Fr=E9d=E9ric_L=2E_W=2E_Meunier?=" Subject: Re: [Bug #14388] keyboard under X with 2.6.31 Date: Mon, 12 Oct 2009 23:54:19 -0300 (BRST) Message-ID: References: <56acieJJ2fF.A.nEB.Hzl0KB@chimera> <87ljjgfcbu.fsf@spindle.srvr.nix> Mime-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="8323328-1177665380-1255402465=:19647" Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:cc:subject :in-reply-to:message-id:references:user-agent:x-archive:mime-version :content-type; bh=a+XwsdWYPTThBJFMfmoU3jhO27RdnLMch1nSqUR6kFE=; b=LgS7jfUyxJg+DoCYG+Y991LQD2KA+fbMgTipI20ksdOI1AY9OLbpPDWr3Uh20U6Hjx 7AVgukvv66QTWQZnwsW7+das3OOhA9f7sLglZNUeTtFnQ1o2I9lm3IpfLJSOhKWkmIpS LWaxhsPuVd3/DLkeZEsxGI9kKDs5PTLI5mdsA= In-Reply-To: Sender: linux-kernel-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: To: Linus Torvalds Cc: Nix , "Justin P. Mattock" , "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Boyan , Dmitry Torokhov , Ed Tomlinson , OGAWA Hirofumi This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323328-1177665380-1255402465=:19647 Content-Type: TEXT/PLAIN; charset="iso-8859-15"; format="flowed" Content-Transfer-Encoding: quoted-printable On Mon, 12 Oct 2009, Linus Torvalds wrote: > On Mon, 12 Oct 2009, Nix wrote: >> On 12 Oct 2009, Justin P. Mattock uttered the following: >> >>> Not sure where this stands. Right now all three machines I have seem t= o be having no issues with the kayboard >>> (xserver 1.6.*) I can go and build the latest xserver(1.7) to see if I = hit something. >> [...] >>>> Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=3D14388 >>>> Subject : keyboard under X with 2.6.31 >>>> Submitter : Fr=E9d=E9ric L. W. Meunier >>>> Date : 2009-10-07 20:19 (5 days old) >>>> First-Bad-Commit: http://git.kernel.org/?p=3Dlinux/kernel/git/torvalds= /linux-2.6.git;a=3Dcommit;h=3De043e42bdb66885b3ac10d27a01ccb9972e2b0a3 >>>> References : http://marc.info/?l=3Dlinux-kernel&m=3D125494753228217= &w=3D4 >> >> I have been seeing problems precisely like those described (sometimes >> the keyboard dies, sometimes it gets 'stuck' with a key held down, until >> I switch TTYs, which generally means killing X as I'm not aware of an >> easy way to switch VTs using only the mouse), since I moved to 2.6.31 > > The particular commit that was bisected to should really not matter for X, > except perhaps from a timing standpoint. > > The problem it fixed was in pty's, and X doesn't use them much if at all > (various X _programs_ may, of course, but the symptoms don't sound like > it's just a particular X app that has issues, but more of a generic X > keyboard handling thing) > > But for non-pty's, there should be no semantic changes from that commit > outside of some general tty timing differences by doing that > tty_flush_to_ldisc() at new points. > > I could fairly easily imagine that some timing difference does expose > another longer-standing problem in either the kernel or X itself. So the > bisection isn't necessarily wrong, it's just not likely telling us what > the real problem is. > > Of course, maybe there is some race condition in the tty_buffer.c code. We > _used_ to not call flush_to_ldisc() except through the workqueue code, so > races would not be seen in normal circumstances. Now that flush_to_ldisc() > could easily get called both synchronously from tty_read()/tty_poll(), > while also being hit from the workqueues. > > Alan, Ogawa-san, do either of you see some problem in tty_buffer.c, > perhaps? Just a note. With me, all the keyboard problems happened while I=20 was under X, but doing something in a terminal running screen.=20 Reverting the commit stopped the problem. --8323328-1177665380-1255402465=:19647--