| Message ID | 2ed3f3aba21a4b815e9497e6aeba497280f9f333.1469126217.git.tom.ty89@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Fri, Jul 22, 2016 at 02:41:54AM +0800, tom.ty89@gmail.com wrote: > @@ -3854,6 +3852,8 @@ static unsigned int ata_scsi_mode_select_xlat(struct ata_queued_cmd *qc) > if (ata_mselect_control(qc, p, pg_len, &fp) < 0) { > fp += hdr_len + bd_len; > goto invalid_param; > + } else { > + goto skip; /* No ATA command to send */ Hmmm... I'm a bit confused. Why is mselect_control path different from mselect_caching in terms of qc handling? Thanks.
As I've mentioned in the comment/message, there is no ATA command needed to be sent to the device, since it only toggles a bit in dev->flags. See that there is no ata_taskfile constructed in ata_mselect_control(). On 22 July 2016 at 05:26, Tejun Heo <tj@kernel.org> wrote: > On Fri, Jul 22, 2016 at 02:41:54AM +0800, tom.ty89@gmail.com wrote: >> @@ -3854,6 +3852,8 @@ static unsigned int ata_scsi_mode_select_xlat(struct ata_queued_cmd *qc) >> if (ata_mselect_control(qc, p, pg_len, &fp) < 0) { >> fp += hdr_len + bd_len; >> goto invalid_param; >> + } else { >> + goto skip; /* No ATA command to send */ > > Hmmm... I'm a bit confused. Why is mselect_control path different > from mselect_caching in terms of qc handling? > > Thanks. > > -- > tejun -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Jul 22, 2016 at 05:50:18AM +0800, Tom Yan wrote: > As I've mentioned in the comment/message, there is no ATA command > needed to be sent to the device, since it only toggles a bit in > dev->flags. See that there is no ata_taskfile constructed in > ata_mselect_control(). But ata_mselect_caching() contructs a tf?
Yes, because it touches an actual ATA drive setting, while D_SENSE is merely a "software setting" stored in dev->flags to make the kernel response differently when build sense data. On 26 July 2016 at 02:30, Tejun Heo <tj@kernel.org> wrote: > On Fri, Jul 22, 2016 at 05:50:18AM +0800, Tom Yan wrote: >> As I've mentioned in the comment/message, there is no ATA command >> needed to be sent to the device, since it only toggles a bit in >> dev->flags. See that there is no ata_taskfile constructed in >> ata_mselect_control(). > > But ata_mselect_caching() contructs a tf? > > -- > tejun -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Jul 22, 2016 at 02:41:54AM +0800, tom.ty89@gmail.com wrote: > From: Tom Yan <tom.ty89@gmail.com> > > scsi_done() was called repeatedly and apparently because of that, > the kernel would call trace when we touch the Control mode page: > > Call Trace: > [<ffffffff812ea0d2>] dump_stack+0x63/0x81 > [<ffffffff81079cfb>] __warn+0xcb/0xf0 > [<ffffffff81079e2d>] warn_slowpath_null+0x1d/0x20 > [<ffffffffa00f51b0>] ata_eh_finish+0xe0/0xf0 [libata] > [<ffffffffa00fb830>] sata_pmp_error_handler+0x640/0xa50 [libata] > [<ffffffffa00470ed>] ahci_error_handler+0x1d/0x70 [libahci] > [<ffffffffa00f55f0>] ata_scsi_port_error_handler+0x430/0x770 [libata] > [<ffffffffa00eff8d>] ? ata_scsi_cmd_error_handler+0xdd/0x160 [libata] > [<ffffffffa00f59d7>] ata_scsi_error+0xa7/0xf0 [libata] > [<ffffffffa00913ba>] scsi_error_handler+0xaa/0x560 [scsi_mod] > [<ffffffffa0091310>] ? scsi_eh_get_sense+0x180/0x180 [scsi_mod] > [<ffffffff81098eb8>] kthread+0xd8/0xf0 > [<ffffffff815d913f>] ret_from_fork+0x1f/0x40 > [<ffffffff81098de0>] ? kthread_worker_fn+0x170/0x170 > ---[ end trace 8b7501047e928a17 ]--- > > Removed the unnecessary code and let ata_scsi_translate() do the job. > > Also, since ata_mselect_control() has no ATA command to send to the > device, ata_scsi_mode_select_xlat() should return 1 for it, so that > ata_scsi_translate() will finish early to avoid ata_qc_issue(). > > Signed-off-by: Tom Yan <tom.ty89@gmail.com> Applied to libata/for-4.9. Thanks.
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 6c424c5..f5c4200 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -3720,8 +3720,6 @@ static int ata_mselect_control(struct ata_queued_cmd *qc, dev->flags |= ATA_DFLAG_D_SENSE; else dev->flags &= ~ATA_DFLAG_D_SENSE; - qc->scsicmd->result = SAM_STAT_GOOD; - qc->scsicmd->scsi_done(qc->scsicmd); return 0; } @@ -3854,6 +3852,8 @@ static unsigned int ata_scsi_mode_select_xlat(struct ata_queued_cmd *qc) if (ata_mselect_control(qc, p, pg_len, &fp) < 0) { fp += hdr_len + bd_len; goto invalid_param; + } else { + goto skip; /* No ATA command to send */ } break; default: /* invalid page code */