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[5/5] ata: libata: fetch sense data for ATA devices supporting sense reporting

Message ID 20220926205257.601750-6-Niklas.Cassel@wdc.com
State New
Headers show
Series fetch sense data for ATA devices supporting sense reporting | expand

Commit Message

Niklas Cassel Sept. 26, 2022, 8:53 p.m. UTC 
From: Niklas Cassel <niklas.cassel@wdc.com>

Currently, the sense data reporting feature set is enabled for all ATA
devices which supports the feature set (ata_id_has_sense_reporting()),
see ata_dev_config_sense_reporting().

However, even if sense data reporting is enabled, and the device
indicates that sense data is available, the sense data is only fetched
for ATA ZAC devices. For regular ATA devices, the available sense data
is never fetched, it is simply ignored. Instead, libata will use the
ERROR + STATUS fields and map them to a very generic and reduced set
of sense data, see ata_gen_ata_sense() and ata_to_sense_error().

When sense data reporting was first implemented, regular ATA devices
did fetch the sense data from the device. However, this was restricted
to only ATA ZAC devices in commit ca156e006add ("libata: don't request
sense data on !ZAC ATA devices").

With recent changes related to sense data and NCQ autosense, we want
to, once again, fetch the sense data for all ATA devices supporting
sense reporting.
ata_gen_ata_sense() should only be used for devices that don't support
the sense data reporting feature set.
hopefully the features will be more robust this time around.

It is not just ZAC, many new ATA features, e.g. Command Duration
Limits, relies on working NCQ autosense and sense data. Therefore,
it is not really an option to avoid fetching the sense data forever.

If we encounter a device that is misbehaving because the sense data is
actually fetched, then that device should be quirked such that it
never enables the sense data reporting feature set in the first place,
since such a device is obviously not compliant with the specification.

The order in which we will try to add sense data to a scsi_cmnd:
1) NCQ autosense (if supported) - ata_eh_analyze_ncq_error()
2) REQUEST SENSE DATA EXT (if supported) - ata_eh_request_sense()
3) error + status field translation - ata_gen_ata_sense(), called
   by ata_scsi_qc_complete() if neither 1) or 2) is supported.

Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com>
---
 drivers/ata/libata-eh.c   | 3 +--
 drivers/ata/libata-sata.c | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 922e6c37ea9b..8610756d7d0a 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1579,6 +1579,7 @@  static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc)
 	}
 
 	switch (qc->dev->class) {
+	case ATA_DEV_ATA:
 	case ATA_DEV_ZAC:
 		/*
 		 * Fetch the sense data explicitly if:
@@ -1589,8 +1590,6 @@  static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc)
 		 */
 		if (!(qc->flags & ATA_QCFLAG_SENSE_VALID) && (stat & ATA_SENSE))
 			ata_eh_request_sense(qc);
-		fallthrough;
-	case ATA_DEV_ATA:
 		if (err & ATA_ICRC)
 			qc->err_mask |= AC_ERR_ATA_BUS;
 		if (err & (ATA_UNC | ATA_AMNF))
diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
index 5d75e62f27b5..464e85d5cd83 100644
--- a/drivers/ata/libata-sata.c
+++ b/drivers/ata/libata-sata.c
@@ -1392,8 +1392,7 @@  static int ata_eh_read_log_10h(struct ata_device *dev,
 	tf->hob_lbah = buf[10];
 	tf->nsect = buf[12];
 	tf->hob_nsect = buf[13];
-	if (dev->class == ATA_DEV_ZAC && ata_id_has_ncq_autosense(dev->id) &&
-	    (tf->status & ATA_SENSE))
+	if (ata_id_has_ncq_autosense(dev->id) && (tf->status & ATA_SENSE))
 		tf->auxiliary = buf[14] << 16 | buf[15] << 8 | buf[16];
 
 	return 0;