From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Jens Axboe <axboe@suse.de>
Cc: linux-ide@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: PATCH (for comment): ide-cd possible race in PIO mode
Date: Wed, 17 Nov 2004 16:25:30 +0000 [thread overview]
Message-ID: <1100708728.420.68.camel@localhost.localdomain> (raw)
In-Reply-To: <20041117153706.GH26240@suse.de>
On Mer, 2004-11-17 at 15:37, Jens Axboe wrote:
> > - HWIF(drive)->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
> > + spin_lock_irqsave(&ide_lock, flags);
> > + HWIF(drive)->OUTBSYNC(WIN_PACKETCMD, IDE_COMMAND_REG);
> > + ndelay(400);
> > + spin_unlock_irqsave(&ide_lock, flags);
> > return (*handler) (drive);
> > }
> > }
>
> What good does the lock do?
The same as in ide_execute_command - make sure we don't take an IDE
interrupt that tries to read the state during the delay. That is the old
2.4 "may drives shared IRQ random fails" fix and why the lock is taken
in ide_execute_command.
next prev parent reply other threads:[~2004-11-17 17:28 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-17 13:19 PATCH (for comment): ide-cd possible race in PIO mode Alan Cox
2004-11-17 15:37 ` Jens Axboe
2004-11-17 16:25 ` Alan Cox [this message]
2004-11-17 20:56 ` Jens Axboe
2004-11-22 7:58 ` Jens Axboe
2004-11-24 11:35 ` Alan Cox
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