[libata] change ata_qc_complete() to take error mask as second arg

The second argument to ata_qc_complete() was being used for two
purposes: communicate the ATA Status register to the completion
function, and indicate an error.  On legacy PCI IDE hardware, the latter
is often implicit in the former.  On more modern hardware, the driver
often completely emulated a Status register value, passing ATA_ERR as an
indication that something went wrong.

Now that previous code changes have eliminated the need to use drv_stat
arg to communicate the ATA Status register value, we can convert it to a
mask of possible error classes.

This will lead to more flexible error handling in the future.

1 files changed, 28 insertions, 18 deletions

diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index 89a04b1a5a0e..1e3792f86fcf 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -560,7 +560,7 @@ void ata_gen_ata_desc_sense(struct ata_queued_cmd *qc)
          * Use ata_to_sense_error() to map status register bits
          * onto sense key, asc & ascq.
          */
-        if (unlikely(tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ))) {
+        if (tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ)) {
                 ata_to_sense_error(qc->ap->id, tf->command, tf->feature,
                                    &sb[1], &sb[2], &sb[3]);
                 sb[1] &= 0x0f;
@@ -635,7 +635,7 @@ void ata_gen_fixed_sense(struct ata_queued_cmd *qc)
          * Use ata_to_sense_error() to map status register bits
          * onto sense key, asc & ascq.
          */
-        if (unlikely(tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ))) {
+        if (tf->command & (ATA_BUSY | ATA_DF | ATA_ERR | ATA_DRQ)) {
                 ata_to_sense_error(qc->ap->id, tf->command, tf->feature,
                                    &sb[2], &sb[12], &sb[13]);
                 sb[2] &= 0x0f;
@@ -644,7 +644,11 @@ void ata_gen_fixed_sense(struct ata_queued_cmd *qc)
         sb[0] = 0x70;
         sb[7] = 0x0a;
 
-        if (tf->flags & ATA_TFLAG_LBA && !(tf->flags & ATA_TFLAG_LBA48)) {
+        if (tf->flags & ATA_TFLAG_LBA48) {
+                /* TODO: find solution for LBA48 descriptors */
+        }
+
+        else if (tf->flags & ATA_TFLAG_LBA) {
                 /* A small (28b) LBA will fit in the 32b info field */
                 sb[0] |= 0x80;          /* set valid bit */
                 sb[3] = tf->device & 0x0f;
@@ -652,6 +656,10 @@ void ata_gen_fixed_sense(struct ata_queued_cmd *qc)
                 sb[5] = tf->lbam;
                 sb[6] = tf->lbal;
         }
+
+        else {
+                /* TODO: C/H/S */
+        }
 }
 
 /**
@@ -1199,10 +1207,12 @@ nothing_to_do:
         return 1;
 }
 
-static int ata_scsi_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat)
+static int ata_scsi_qc_complete(struct ata_queued_cmd *qc,
+                                unsigned int err_mask)
 {
         struct scsi_cmnd *cmd = qc->scsicmd;
-        int need_sense = drv_stat & (ATA_ERR | ATA_BUSY | ATA_DRQ);
+        u8 *cdb = cmd->cmnd;
+        int need_sense = (err_mask != 0);
 
         /* For ATA pass thru (SAT) commands, generate a sense block if
          * user mandated it or if there's an error.  Note that if we
@@ -1211,8 +1221,8 @@ static int ata_scsi_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat)
          * whether the command completed successfully or not. If there
          * was no error, SK, ASC and ASCQ will all be zero.
          */
-        if (((cmd->cmnd[0] == ATA_16) || (cmd->cmnd[0] == ATA_12)) &&
-            ((cmd->cmnd[2] & 0x20) || need_sense)) {
+        if (((cdb[0] == ATA_16) || (cdb[0] == ATA_12)) &&
+            ((cdb[2] & 0x20) || need_sense)) {
                 ata_gen_ata_desc_sense(qc);
         } else {
                 if (!need_sense) {
@@ -1995,21 +2005,13 @@ void atapi_request_sense(struct ata_port *ap, struct ata_device *dev,
         DPRINTK("EXIT\n");
 }
 
-static int atapi_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat)
+static int atapi_qc_complete(struct ata_queued_cmd *qc, unsigned int err_mask)
 {
         struct scsi_cmnd *cmd = qc->scsicmd;
 
-        VPRINTK("ENTER, drv_stat == 0x%x\n", drv_stat);
-
-        if (unlikely(drv_stat & (ATA_BUSY | ATA_DRQ)))
-                /* FIXME: not quite right; we don't want the
-                 * translation of taskfile registers into
-                 * a sense descriptors, since that's only
-                 * correct for ATA, not ATAPI
-                 */
-                ata_gen_ata_desc_sense(qc);
+        VPRINTK("ENTER, err_mask 0x%X\n", err_mask);
 
-        else if (unlikely(drv_stat & ATA_ERR)) {
+        if (unlikely(err_mask & AC_ERR_DEV)) {
                 DPRINTK("request check condition\n");
 
                 /* FIXME: command completion with check condition
@@ -2026,6 +2028,14 @@ static int atapi_qc_complete(struct ata_queued_cmd *qc, u8 drv_stat)
                 return 1;
         }
 
+        else if (unlikely(err_mask))
+                /* FIXME: not quite right; we don't want the
+                 * translation of taskfile registers into
+                 * a sense descriptors, since that's only
+                 * correct for ATA, not ATAPI
+                 */
+                ata_gen_ata_desc_sense(qc);
+
         else {
                 u8 *scsicmd = cmd->cmnd;