From: Jens Axboe <axboe@suse.de>
To: Alan Chandler <alan@chandlerfamily.org.uk>
Cc: linux-kernel@vger.kernel.org
Subject: Re: ide-cd problem
Date: Sun, 21 Nov 2004 09:56:36 +0100 [thread overview]
Message-ID: <20041121085636.GG26240@suse.de> (raw)
In-Reply-To: <200411210053.45065.alan@chandlerfamily.org.uk>
On Sun, Nov 21 2004, Alan Chandler wrote:
> On Saturday 20 November 2004 19:47, Jens Axboe wrote:
> > On Sat, Nov 20 2004, Alan Chandler wrote:
> ...
> > > Normally, because the requested data_len is not zero, the data is
> > > sent. In this case however, because the original request had nothing
> > > to send, the while/if clauses to initiate a new transfer are skipped
> > > and the routine ends up setting a new interrupt handler address and
> > > returning to await an interrupt that will never come.
> >
> > The big question is - what does the original command look like? Just
> > dumping rq->cmd[0] would be a big help, but really just put code in
> > sg_io() in block/scsi_ioctl.c to dump the completed sg_io_hdr_t and send
> > that.
>
> I haven't dumped the whole request header, but the command (after it has been
> retrieved from the user) and the dxfer_length. Is there anything else I
> should dump?
No that's fine, that's all I need.
> Here is the output leading up to the point where ide-cd hangs because the IO
> is just left pending
>
> Nov 21 00:44:20 kanger kernel: sg_io command length 10
> Nov 21 00:44:20 kanger kernel: sg_io command [0] = 0x3c
> Nov 21 00:44:20 kanger kernel: sg_io command [1] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [2] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [3] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [4] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [5] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [6] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [7] = 0xfc
> Nov 21 00:44:20 kanger kernel: sg_io command [8] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [9] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io dxfer_len = 64512
> Nov 21 00:44:20 kanger kernel: sg_io command length 10
> Nov 21 00:44:20 kanger kernel: sg_io command [0] = 0x3c
> Nov 21 00:44:20 kanger kernel: sg_io command [1] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [2] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [3] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [4] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [5] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [6] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [7] = 0xfc
> Nov 21 00:44:20 kanger kernel: sg_io command [8] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [9] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io dxfer_len = 64512
> Nov 21 00:44:20 kanger kernel: sg_io command length 10
> Nov 21 00:44:20 kanger kernel: sg_io command [0] = 0x3c
> Nov 21 00:44:20 kanger kernel: sg_io command [1] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [2] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [3] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [4] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [5] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [6] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [7] = 0xfc
> Nov 21 00:44:20 kanger kernel: sg_io command [8] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [9] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io dxfer_len = 64512
> Nov 21 00:44:20 kanger kernel: sg_io command length 10
> Nov 21 00:44:20 kanger kernel: sg_io command [0] = 0x3c
> Nov 21 00:44:20 kanger kernel: sg_io command [1] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [2] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [3] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [4] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [5] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [6] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [7] = 0xfc
> Nov 21 00:44:20 kanger kernel: sg_io command [8] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [9] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io dxfer_len = 64512
> Nov 21 00:44:20 kanger kernel: sg_io command length 6
> Nov 21 00:44:20 kanger kernel: sg_io command [0] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [1] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [2] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [3] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [4] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [5] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io dxfer_len = 0
> Nov 21 00:44:20 kanger kernel: sg_io command length 6
> Nov 21 00:44:20 kanger kernel: sg_io command [0] = 0x1b
> Nov 21 00:44:20 kanger kernel: sg_io command [1] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [2] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [3] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io command [4] = 0x3
> Nov 21 00:44:20 kanger kernel: sg_io command [5] = 0x0
> Nov 21 00:44:20 kanger kernel: sg_io dxfer_len = 0
> Nov 21 00:45:00 kanger kernel: hdc: lost interrupt
> Nov 21 00:45:40 kanger kernel: hdc: lost interrupt
> Nov 21 00:47:00 kanger last message repeated 2 times
> Nov 21 00:47:40 kanger kernel: hdc: lost interrupt
So the last request is a START_STOP unit, which doesn't transfer any
data. If the drive has DRQ_STAT stat set here, it looks very odd. Any
chance you could instrument cdrom_newpc_intr() as well to dump status
bytes and expected transfer lengths from the drive?
--
Jens Axboe
next prev parent reply other threads:[~2004-11-21 8:57 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-20 18:42 ide-cd problem Alan Chandler
2004-11-20 19:47 ` Jens Axboe
2004-11-21 0:53 ` Alan Chandler
2004-11-21 8:56 ` Jens Axboe [this message]
2004-11-21 10:25 ` Alan Chandler
2004-11-21 16:13 ` Alan Chandler
2004-11-22 7:52 ` Alan Chandler
2004-11-22 8:01 ` Jens Axboe
2004-11-22 10:30 ` Alan Chandler
2004-11-22 10:51 ` Jens Axboe
2004-11-22 11:29 ` Alan Chandler
2004-11-22 11:31 ` Jens Axboe
2004-11-22 12:53 ` Alan Chandler
2004-11-22 13:02 ` Jens Axboe
2004-11-22 19:19 ` Alan Chandler
2004-11-22 23:48 ` Alan Chandler
2004-11-23 7:13 ` Alan Chandler
2004-11-23 14:51 ` Jens Axboe
2004-11-23 21:49 ` Alan Chandler
2004-11-26 23:39 ` Alan Chandler
2004-11-29 17:29 ` Bill Davidsen
2004-11-30 8:59 ` Alan Chandler
2004-12-10 21:32 ` ide-cd problem revisited - more brainpower needed Alan Chandler
2004-12-10 23:14 ` Alan Cox
2004-12-12 0:17 ` Alan Chandler
2004-12-12 11:39 ` Alan Cox
2004-12-12 13:34 ` Alan Chandler
2004-12-14 0:20 ` Alan Chandler
2004-12-16 15:56 ` Bill Davidsen
2004-12-17 23:59 ` Alan Chandler
2004-11-24 23:19 ` ide-cd problem Alan Cox
2004-11-25 15:29 ` Jens Axboe
2004-11-25 16:25 ` Alan Cox
2004-11-25 18:12 ` Jens Axboe
2004-11-25 18:45 ` Alan Chandler
2004-11-23 18:34 ` Jeff Garzik
2004-11-23 19:13 ` Jens Axboe
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