From: Johannes Stezenbach <js@convergence.de>
To: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
Cc: Matthias Andree <matthias.andree@gmx.de>,
Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] barrier patch set
Date: Sat, 20 Mar 2004 03:53:12 +0100 [thread overview]
Message-ID: <20040320025312.GA12710@convergence.de> (raw)
In-Reply-To: <200403200313.05681.bzolnier@elka.pw.edu.pl>
Bartlomiej Zolnierkiewicz wrote:
> On Saturday 20 of March 2004 02:48, Johannes Stezenbach wrote:
>
> > hdparm -i and -I ultimately both interpret WIN_IDENTIFY result, and both
> > test bit 0x0020 of word 85. So it's unclear to me why they report a
> > different write cache setting. I added a hexdump to dump_identity()
> > in hdparm.c, and found that bit 0x0020 of word 85 is always set.
>
> or WIN_PIDENTIFY to be strict but
>
> -i returns _cached_ (read when the device was probed) identify data
> (uses HDIO_GET_IDENTIFY ioctl)
> -I reads _current_ data directly from the device
> (uses HDIO_DRIVE_CMD ioctl)
Oh, right.
But: HDIO_GET_IDENTITY returns drive->id, and surely drive->id
is used internally. So isn't it a bug that drive->id is not
updated when the write cache setting is changed?
I think the barrier code uses drive->id to determine if the
write cache is enabled.
Johannes
next prev parent reply other threads:[~2004-03-20 2:53 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-03-19 15:35 [PATCH] barrier patch set Jens Axboe
2004-03-19 16:30 ` Mika Penttilä
2004-03-19 18:16 ` Jens Axboe
2004-03-19 18:44 ` Mika Penttilä
2004-03-20 9:55 ` Jens Axboe
2004-03-19 16:34 ` Jeff Garzik
2004-03-19 18:19 ` Jens Axboe
2004-03-19 23:01 ` Matthias Andree
2004-03-20 0:02 ` Bartlomiej Zolnierkiewicz
2004-03-20 1:48 ` Johannes Stezenbach
2004-03-20 2:13 ` Bartlomiej Zolnierkiewicz
2004-03-20 2:53 ` Johannes Stezenbach [this message]
2004-03-20 16:03 ` Bartlomiej Zolnierkiewicz
2004-03-20 11:36 ` Matthias Andree
2004-03-20 16:00 ` Bartlomiej Zolnierkiewicz
2004-03-20 23:36 ` Johannes Stezenbach
2004-03-21 1:33 ` Bartlomiej Zolnierkiewicz
2004-03-20 18:52 ` Helge Hafting
2004-03-22 11:15 ` Matthias Andree
2004-03-19 23:59 ` Bartlomiej Zolnierkiewicz
2004-03-20 0:14 ` Jeff Garzik
2004-03-20 0:40 ` Bartlomiej Zolnierkiewicz
2004-03-20 0:42 ` Jeff Garzik
2004-03-20 1:24 ` Bartlomiej Zolnierkiewicz
2004-03-20 9:58 ` Jens Axboe
2004-03-20 10:12 ` Jeff Garzik
2004-03-20 10:19 ` Jens Axboe
2004-03-20 10:37 ` Jeff Garzik
2004-03-20 16:30 ` Bartlomiej Zolnierkiewicz
2004-03-21 18:12 ` Jeff Garzik
2004-03-20 10:21 ` Jeff Garzik
2004-03-20 15:54 ` Bartlomiej Zolnierkiewicz
2004-03-20 0:17 ` Jeff Garzik
2004-03-20 9:53 ` Jens Axboe
2004-03-20 16:23 ` Bartlomiej Zolnierkiewicz
2004-03-20 16:27 ` Jens Axboe
2004-03-20 16:32 ` Chris Mason
2004-03-20 17:05 ` Bartlomiej Zolnierkiewicz
2004-03-20 17:10 ` Chris Mason
2004-03-20 20:16 ` Bartlomiej Zolnierkiewicz
2004-03-21 9:43 ` Jens Axboe
2004-03-30 16:04 ` Stephen C. Tweedie
2004-03-30 19:19 ` Chris Mason
2004-03-30 21:50 ` Stephen C. Tweedie
2004-03-30 22:13 ` Chris Mason
2004-03-31 14:03 ` Stephen C. Tweedie
2004-03-31 14:27 ` Chris Mason
2004-03-31 18:28 ` Ric Wheeler
2004-03-30 22:21 ` Jeff Garzik
2004-03-30 22:36 ` Chris Wedgwood
2004-03-30 22:39 ` Jeff Garzik
2004-03-30 22:41 ` Chris Wedgwood
2004-03-30 22:40 ` Bartlomiej Zolnierkiewicz
2004-03-30 22:38 ` Jeff Garzik
2004-03-31 14:08 ` Stephen C. Tweedie
2004-03-31 14:21 ` Chris Mason
2004-03-31 21:26 ` Jeff Garzik
2004-03-31 22:09 ` Chris Mason
2004-03-31 21:27 ` Jeff Garzik
2004-03-19 16:48 ` Marc-Christian Petersen
2004-03-19 18:19 ` Jens Axboe
2004-03-22 11:09 ` Andrew Morton
2004-03-22 11:10 ` Jens Axboe
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