From ca156e006add67e4beea7896be395160735e09b0 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Mon, 24 Jun 2019 09:32:50 -0700
Subject: [PATCH] libata: don't request sense data on !ZAC ATA devices
Git-commit: ca156e006add67e4beea7896be395160735e09b0
Patch-mainline: v5.3-rc1
References: bsc#1051510

ZAC support added sense data requesting on error for both ZAC and ATA
devices. This seems to cause erratic error handling behaviors on some
SSDs where the device reports sense data availability and then
delivers the wrong content making EH take the wrong actions.  The
failure mode was sporadic on a LITE-ON ssd and couldn't be reliably
reproduced.

There is no value in requesting sense data from non-ZAC ATA devices
while there's a significant risk of introducing EH misbehaviors which
are difficult to reproduce and fix.  Let's do the sense data dancing
only for ZAC devices.

Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Masato Suzuki <masato.suzuki@wdc.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/ata/libata-eh.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 9d687e1d4325..3bfd9da58473 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1469,7 +1469,7 @@ 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 (ata_id_has_ncq_autosense(dev->id))
+	if (dev->class == ATA_DEV_ZAC && ata_id_has_ncq_autosense(dev->id))
 		tf->auxiliary = buf[14] << 16 | buf[15] << 8 | buf[16];
 
 	return 0;
@@ -1716,7 +1716,8 @@ void ata_eh_analyze_ncq_error(struct ata_link *link)
 	memcpy(&qc->result_tf, &tf, sizeof(tf));
 	qc->result_tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
 	qc->err_mask |= AC_ERR_DEV | AC_ERR_NCQ;
-	if ((qc->result_tf.command & ATA_SENSE) || qc->result_tf.auxiliary) {
+	if (dev->class == ATA_DEV_ZAC &&
+	    ((qc->result_tf.command & ATA_SENSE) || qc->result_tf.auxiliary)) {
 		char sense_key, asc, ascq;
 
 		sense_key = (qc->result_tf.auxiliary >> 16) & 0xff;
@@ -1770,10 +1771,11 @@ static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc,
 	}
 
 	switch (qc->dev->class) {
-	case ATA_DEV_ATA:
 	case ATA_DEV_ZAC:
 		if (stat & ATA_SENSE)
 			ata_eh_request_sense(qc, qc->scsicmd);
+		/* fall through */
+	case ATA_DEV_ATA:
 		if (err & ATA_ICRC)
 			qc->err_mask |= AC_ERR_ATA_BUS;
 		if (err & (ATA_UNC | ATA_AMNF))
-- 
2.16.4