From: Jens Axboe <axboe@suse.de>
To: Rachita Kothiyal <rachita@in.ibm.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [RFC] Patch to fix cdrom being confused on using kdump
Date: Sun, 9 Apr 2006 12:29:42 +0200 [thread overview]
Message-ID: <20060409102942.GI3859@suse.de> (raw)
In-Reply-To: <20060407135714.GA25569@in.ibm.com>
On Fri, Apr 07 2006, Rachita Kothiyal wrote:
> Hi Jens
>
> As we had discussed earlier, I had seen the cdrom drive appearing
> confused on using kdump on certain x86_64 systems. During the booting
> up of the second kernel, the following message would keep flooding
> the console, and the booting would not proceed any further.
>
> hda: cdrom_pc_intr: The drive appears confused (ireason = 0x01)
>
> In this patch, whenever we are hitting a confused state in the interrupt
> handler with the DRQ set, we clear the DSC bit of the status register and
> return 'ide_stopped' from the interrupt handler.
>
> Please provide your comments and feedback.
>
> Thanks
> Rachita
>
>
> Signed-off-by: Rachita Kothiyal <rachita@in.ibm.com>
> ---
>
> drivers/ide/ide-cd.c | 5 +++++
> 1 files changed, 5 insertions(+)
>
> diff -puN drivers/ide/ide-cd.c~cdrom-confused-clrinterrupt drivers/ide/ide-cd.c
> --- linux-2.6.16-mm2/drivers/ide/ide-cd.c~cdrom-confused-clrinterrupt 2006-03-29 11:23:18.000000000 +0530
> +++ linux-2.6.16-mm2-rachita/drivers/ide/ide-cd.c 2006-04-07 19:05:48.962710872 +0530
> @@ -1450,6 +1450,11 @@ static ide_startstop_t cdrom_pc_intr (id
> rq->sense_len += thislen;
> } else {
> confused:
> + if (( stat & DRQ_STAT) == DRQ_STAT) {
if (stat & DRQ_STAT)
checking for DRQ_STAT again doesn't make sense, how can it ever be
anything but DRQ_STAT if DRQ_STAT is set?
> + /* DRQ is set. Interrupt not welcome now. Ignore */
> + HWIF(drive)->OUTB((stat & 0xEF), IDE_STATUS_REG);
> + return ide_stopped;
And this looks very wrong, you can't write to the status register. Well
you can, but then it's the command register! Writing stat & 0xef to the
command register is an odd thing to do. I think you just want to clear
the DRQ bit, which should be fine after it was read initially. How about
if (stat & DRQ_STAT)
return ide_stopped;
Can you test that?
--
Jens Axboe
next prev parent reply other threads:[~2006-04-09 10:29 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-04-07 13:57 [RFC] Patch to fix cdrom being confused on using kdump Rachita Kothiyal
2006-04-07 15:07 ` Dave Hansen
2006-04-09 10:29 ` Jens Axboe [this message]
2006-04-11 15:31 ` Rachita Kothiyal
2006-04-11 17:03 ` Jens Axboe
2006-04-12 11:29 ` Rachita Kothiyal
2006-04-19 13:29 ` Rachita Kothiyal
2006-04-19 13:52 ` Jens Axboe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20060409102942.GI3859@suse.de \
--to=axboe@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=rachita@in.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).