Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761102AbZJNA4c (ORCPT ); Tue, 13 Oct 2009 20:56:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760777AbZJNA4b (ORCPT ); Tue, 13 Oct 2009 20:56:31 -0400 Received: from mail-yx0-f188.google.com ([209.85.210.188]:49366 "EHLO mail-yx0-f188.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759101AbZJNA4a (ORCPT ); Tue, 13 Oct 2009 20:56:30 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:in-reply-to:message-id:references :user-agent:x-archive:mime-version:content-type; b=Z6SUN1mB8lhvnzwSoymVV2teviwsZvU8v1AETgVOaE5rlOX5g7aSB53VQUgYzDSAVs GHX2G5GT1hACqUjDTn5sIVM2Ob3+NKWSwzAu2bKWcpjvPsGA7bDdhXiM0zC+ssIaVbER 4nI0x6gOxO4NAgVKmNjQjsE4nIxRjRF9z/hl4= Date: Tue, 13 Oct 2009 21:55:25 -0300 (BRST) From: "=?ISO-8859-15?Q?Fr=E9d=E9ric_L=2E_W=2E_Meunier?=" To: Linus Torvalds cc: Boyan , "Justin P. Mattock" , Nix , Alan Cox , Paul Fulghum , "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Dmitry Torokhov , Ed Tomlinson , OGAWA Hirofumi Subject: Re: [Bug #14388] keyboard under X with 2.6.31 In-Reply-To: Message-ID: References: <56acieJJ2fF.A.nEB.Hzl0KB@chimera> <87ljjgfcbu.fsf@spindle.srvr.nix> <4AD3F769.5080405@gmail.com> <4AD437F9.9020708@yahoo.co.uk> <4AD4DE4C.4010402@yahoo.co.uk> User-Agent: Alpine 2.01 (LNX 1266 2009-07-14) X-Archive: encrypt MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3234 Lines: 103 On Tue, 13 Oct 2009, Linus Torvalds wrote: > > Another bug: > > On Tue, 13 Oct 2009, Linus Torvalds wrote: >> if (!count) { >> - if (head->next == NULL) >> - break; > > Those two lines should _not_ be deleted. I cleaned up a bit too much. > > The rule is that we must not free the last buffer, because it's also going > to be 'tail'. > > So here's a new version with that fixed (and the previous bug I already > mentioned). > > Whether it _works_ is still not clear. It might eat your pet goldfish, or > make farting noises in your general direction. Or it might fix the bug. > Who knows? > > Linus > > --- > drivers/char/tty_buffer.c | 29 +++++++++++++---------------- > 1 files changed, 13 insertions(+), 16 deletions(-) > > diff --git a/drivers/char/tty_buffer.c b/drivers/char/tty_buffer.c > index 3108991..0296612 100644 > --- a/drivers/char/tty_buffer.c > +++ b/drivers/char/tty_buffer.c > @@ -402,28 +402,26 @@ static void flush_to_ldisc(struct work_struct *work) > container_of(work, struct tty_struct, buf.work.work); > unsigned long flags; > struct tty_ldisc *disc; > - struct tty_buffer *tbuf, *head; > - char *char_buf; > - unsigned char *flag_buf; > > disc = tty_ldisc_ref(tty); > if (disc == NULL) /* !TTY_LDISC */ > return; > > spin_lock_irqsave(&tty->buf.lock, flags); > - /* So we know a flush is running */ > - set_bit(TTY_FLUSHING, &tty->flags); > - head = tty->buf.head; > - if (head != NULL) { > - tty->buf.head = NULL; > - for (;;) { > - int count = head->commit - head->read; > + > + if (!test_and_set_bit(TTY_FLUSHING, &tty->flags)) { > + struct tty_buffer *head; > + while ((head = tty->buf.head) != NULL) { > + int count; > + char *char_buf; > + unsigned char *flag_buf; > + > + count = head->commit - head->read; > if (!count) { > if (head->next == NULL) > break; > - tbuf = head; > - head = head->next; > - tty_buffer_free(tty, tbuf); > + tty->buf.head = head->next; > + tty_buffer_free(tty, head); > continue; > } > /* Ldisc or user is trying to flush the buffers > @@ -445,9 +443,9 @@ static void flush_to_ldisc(struct work_struct *work) > flag_buf, count); > spin_lock_irqsave(&tty->buf.lock, flags); > } > - /* Restore the queue head */ > - tty->buf.head = head; > + clear_bit(TTY_FLUSHING, &tty->flags); > } > + > /* We may have a deferred request to flush the input buffer, > if so pull the chain under the lock and empty the queue */ > if (test_bit(TTY_FLUSHPENDING, &tty->flags)) { > @@ -455,7 +453,6 @@ static void flush_to_ldisc(struct work_struct *work) > clear_bit(TTY_FLUSHPENDING, &tty->flags); > wake_up(&tty->read_wait); > } > - clear_bit(TTY_FLUSHING, &tty->flags); > spin_unlock_irqrestore(&tty->buf.lock, flags); > > tty_ldisc_deref(disc); For now (more than 3h), it isn't doing any harm. And no keyboard lockups. BTW, the old version of the patch was funny. It booted, but at the login prompt I could only enter the first letter. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/