Merge tag 'ata-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux

Pull ata fix from Niklas Cassel:

 - Revert a recent change to sense data generation.

   Sense data can be in either fixed format or descriptor format.

   The D_SENSE bit in the Control mode page controls which format to
   generate. All places but one respected the D_SENSE bit.

   The recent change fixed the one place that didn't respect the D_SENSE
   bit. However, it turns out that hdparm, hddtemp and udisks
   (incorrectly) assumes sense data in descriptor format.

   Therefore, even while the change was technically correct, revert it,
   since even if these user space programs are fixed to (correctly) look
   at the format type before parsing the data, older versions of these
   tools will be around roughly forever.

* tag 'ata-6.11-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
  Revert "ata: libata-scsi: Honor the D_SENSE bit for CK_COND=1 and no error"

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index d6f5e25e1ed8..473e00a58a8b 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -951,8 +951,19 @@ static void ata_gen_passthru_sense(struct ata_queued_cmd *qc)
 				   &sense_key, &asc, &ascq);
 		ata_scsi_set_sense(qc->dev, cmd, sense_key, asc, ascq);
 	} else {
-		/* ATA PASS-THROUGH INFORMATION AVAILABLE */
-		ata_scsi_set_sense(qc->dev, cmd, RECOVERED_ERROR, 0, 0x1D);
+		/*
+		 * ATA PASS-THROUGH INFORMATION AVAILABLE
+		 *
+		 * Note: we are supposed to call ata_scsi_set_sense(), which
+		 * respects the D_SENSE bit, instead of unconditionally
+		 * generating the sense data in descriptor format. However,
+		 * because hdparm, hddtemp, and udisks incorrectly assume sense
+		 * data in descriptor format, without even looking at the
+		 * RESPONSE CODE field in the returned sense data (to see which
+		 * format the returned sense data is in), we are stuck with
+		 * being bug compatible with older kernels.
+		 */
+		scsi_build_sense(cmd, 1, RECOVERED_ERROR, 0, 0x1D);
 	}
 }