isci is needlessly tying libata's hands by returning
SAM_STAT_CHECK_CONDITION to some ata errors. Instead, prefer
SAS_PROTO_RESPONSE to let libata (via sas_ata_task_done()) disposition
the device-to-host fis.
For example isci is triggering an HSM Violation where AHCI is showing a
simple media error for the same bus condition:
isci:
ata7.00: failed command: READ VERIFY SECTOR(S)
ata7.00: cmd 40/00:01:00:00:00/00:00:00:00:00/e0 tag 0
res 01/04:00:00:00:00/00:00:00:00:00/e0 Emask 0x3 (HSM violation)
ahci:
ata6.00: failed command: READ VERIFY SECTOR(S)
ata6.00: cmd 40/00:01:00:00:00/00:00:00:00:00/e0 tag 0
res 51/40:01:00:00:00/00:00:00:00:00/e0 Emask 0x9 (media error)
Note that the isci response matches this from sas_ata_task_done():
/* We saw a SAS error. Send a vague error. */
[..]
dev->sata_dev.fis[3] = 0x04; /* status err */
dev->sata_dev.fis[2] = ATA_ERR;
The end effect is that isci is needlessly triggering hard resets when
they are not necessary.
Cc: <stable@xxxxxxxxxxxxxxx>
Reported-by: Xun Ni <xun.ni@xxxxxxxxx>
Tested-by: Nelson Cheng <nelson.cheng@xxxxxxxxx>
Acked-by: Lukasz Dorau <lukasz.dorau@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/scsi/isci/request.c | 8 ++------
1 files changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/scsi/isci/request.c b/drivers/scsi/isci/request.c
index 99d2930b18c8..56e38096f0c4 100644
--- a/drivers/scsi/isci/request.c
+++ b/drivers/scsi/isci/request.c
@@ -2723,13 +2723,9 @@ static void isci_process_stp_response(struct sas_task *task, struct dev_to_host_
memcpy(resp->ending_fis, fis, sizeof(*fis));
ts->buf_valid_size = sizeof(*resp);
- /* If the device fault bit is set in the status register, then
- * set the sense data and return.
- */
- if (fis->status & ATA_DF)
+ /* If an error is flagged let libata decode the fis */
+ if (ac_err_mask(fis->status))
ts->stat = SAS_PROTO_RESPONSE;
- else if (fis->status & ATA_ERR)
- ts->stat = SAM_STAT_CHECK_CONDITION;
else
ts->stat = SAM_STAT_GOOD;
--
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