1 files changed, 22 insertions, 3 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index de6c60320f6f..829cc37abc41 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1434,6 +1434,8 @@ static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
 #error RC16_LEN must not be more than SD_BUF_SIZE
 #endif
 
+#define READ_CAPACITY_RETRIES_ON_RESET  10
+
 static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
                                                 unsigned char *buffer)
 {
@@ -1441,7 +1443,7 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
         struct scsi_sense_hdr sshdr;
         int sense_valid = 0;
         int the_result;
-        int retries = 3;
+        int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
         unsigned int alignment;
         unsigned long long lba;
         unsigned sector_size;
@@ -1470,6 +1472,13 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
                                  * Invalid Field in CDB, just retry
                                  * silently with RC10 */
                                 return -EINVAL;
+                        if (sense_valid &&
+                            sshdr.sense_key == UNIT_ATTENTION &&
+                            sshdr.asc == 0x29 && sshdr.ascq == 0x00)
+                                /* Device reset might occur several times,
+                                 * give it one more chance */
+                                if (--reset_retries > 0)
+                                        continue;
                 }
                 retries--;
 
@@ -1528,7 +1537,7 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
         struct scsi_sense_hdr sshdr;
         int sense_valid = 0;
         int the_result;
-        int retries = 3;
+        int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
         sector_t lba;
         unsigned sector_size;
 
@@ -1544,8 +1553,16 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
                 if (media_not_present(sdkp, &sshdr))
                         return -ENODEV;
 
-                if (the_result)
+                if (the_result) {
                         sense_valid = scsi_sense_valid(&sshdr);
+                        if (sense_valid &&
+                            sshdr.sense_key == UNIT_ATTENTION &&
+                            sshdr.asc == 0x29 && sshdr.ascq == 0x00)
+                                /* Device reset might occur several times,
+                                 * give it one more chance */
+                                if (--reset_retries > 0)
+                                        continue;
+                }
                 retries--;
 
         } while (the_result && retries);
@@ -1574,6 +1591,8 @@ static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
 
 static int sd_try_rc16_first(struct scsi_device *sdp)
 {
+        if (sdp->host->max_cmd_len < 16)
+                return 0;
         if (sdp->scsi_level > SCSI_SPC_2)
                 return 1;
         if (scsi_device_protection(sdp))