From: Bart Van Assche <bvanassche@acm.org>
To: Michael Wu <michael@allwinnertech.com>,
jejb@linux.ibm.com, martin.petersen@oracle.com
Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] scsi: core: Fix block I/O error of USB card reader during resume
Date: Wed, 17 Aug 2022 06:52:14 -0700 [thread overview]
Message-ID: <ceba3c96-5f32-9b5a-bacc-0eb942b9b90b@acm.org> (raw)
In-Reply-To: <20220817083438.118293-1-michael@allwinnertech.com>
On 8/17/22 01:34, Michael Wu wrote:
> When accessing storage device via an USB card reader, a block I/O error
> occurs during resume:
>
> PM: suspend exit
> sd 0: 0:0:0: [sda] tag#0 UNKNOWN(0x2003) Result: hostbyte=0x00 driverbyte
> =0x08
> sd 0: 0:0:0: [sda] tag#0 Sense Key : 0x6 [current]
> sd 0: 0:0:0: [sda] tag#0 ASC=0x28 ASCQ=0x0
> sd 0: 0:0:0: [sda] tag#0 CDB: opcode=0x28 28 00 00 17 ce e1 00 00 f0 00
> blk_update_request: I/O error, dev sda, sector 1560289 op 0x0:(READ) flags
> 0x84700 phys_seg 19 prio class 0
> sd 0: 0:0:0: [sda] tag#0 device offline or changed
>
> Fix it by changing the action in scsi_io_completion_action() from
> ACTION_FAIL to ACTION_RETRY by adding the condition `cmd->device->
> lockable`.
>
> Signed-off-by: Michael Wu <michael@allwinnertech.com>
> ---
> drivers/scsi/scsi_lib.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index 4dbd29ab1dcc..4bc480721947 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -704,7 +704,8 @@ static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)
> } else if (sense_valid && sense_current) {
> switch (sshdr.sense_key) {
> case UNIT_ATTENTION:
> - if (cmd->device->removable) {
> + if (cmd->device->removable &&
> + cmd->device->lockable) {
> /* Detected disc change. Set a bit
> * and quietly refuse further access.
> */
To me the above doesn't look like a good way to address this. I don't
see why a device being lockable should control whether or not a unit
attention results in a retry? Shouldn't the decision taken by
scsi_io_completion_action() depend on the ASC and ASCQ codes rather than
on whether a device is removable and/or lockable?
BTW, the code modified by the above patch is old. This is what I found
in the 2002 version of scsi_lib.c:
if ((SCpnt->sense_buffer[0] & 0x7f) == 0x70
&& (SCpnt->sense_buffer[2] & 0xf) == UNIT_ATTENTION) {
if (SCpnt->device->removable) {
/* detected disc change. set a bit and quietly refuse
* further access.
*/
SCpnt->device->changed = 1;
SCpnt = scsi_end_request(SCpnt, 0, this_count);
return;
} else {
/*
* Must have been a power glitch, or a
* bus reset. Could not have been a
* media change, so we just retry the
* request and see what happens.
*/
scsi_queue_next_request(q, SCpnt);
return;
}
Bart.
Thanks,
Bart.
next prev parent reply other threads:[~2022-08-17 13:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-17 8:34 [PATCH] scsi: core: Fix block I/O error of USB card reader during resume Michael Wu
2022-08-17 13:52 ` Bart Van Assche [this message]
2022-08-23 10:16 ` Michael Wu
2022-08-26 22:05 ` Bart Van Assche
2022-08-29 9:06 ` Michael Wu
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=ceba3c96-5f32-9b5a-bacc-0eb942b9b90b@acm.org \
--to=bvanassche@acm.org \
--cc=jejb@linux.ibm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=martin.petersen@oracle.com \
--cc=michael@allwinnertech.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).