[SCSI] sr: fix test unit ready responses

Commit 210ba1d1724f5c4ed87a2ab1a21ca861a915f734 updated sr.c to use
the scsi_test_unit_ready() function.  Unfortunately, this has the
wrong characteristic of eating NOT_READY returns which sr.c relies on
for tray status.

Fix by rolling an internal sr_test_unit_ready() that doesn't do this.

Tested-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 27 insertions, 22 deletions

diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 50ba4925020..208565bdbe8 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -163,6 +163,29 @@ static void scsi_cd_put(struct scsi_cd *cd)
         mutex_unlock(&sr_ref_mutex);
 }
 
+/* identical to scsi_test_unit_ready except that it doesn't
+ * eat the NOT_READY returns for removable media */
+int sr_test_unit_ready(struct scsi_device *sdev, struct scsi_sense_hdr *sshdr)
+{
+        int retries = MAX_RETRIES;
+        int the_result;
+        u8 cmd[] = {TEST_UNIT_READY, 0, 0, 0, 0, 0 };
+
+        /* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION
+         * conditions are gone, or a timeout happens
+         */
+        do {
+                the_result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL,
+                                              0, sshdr, SR_TIMEOUT,
+                                              retries--);
+
+        } while (retries > 0 &&
+                 (!scsi_status_is_good(the_result) ||
+                  (scsi_sense_valid(sshdr) &&
+                   sshdr->sense_key == UNIT_ATTENTION)));
+        return the_result;
+}
+
 /*
  * This function checks to see if the media has been changed in the
  * CDROM drive.  It is possible that we have already sensed a change,
@@ -185,8 +208,7 @@ static int sr_media_change(struct cdrom_device_info *cdi, int slot)
         }
 
         sshdr =  kzalloc(sizeof(*sshdr), GFP_KERNEL);
-        retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES,
-                                      sshdr);
+        retval = sr_test_unit_ready(cd->device, sshdr);
         if (retval || (scsi_sense_valid(sshdr) &&
                        /* 0x3a is medium not present */
                        sshdr->asc == 0x3a)) {
@@ -733,10 +755,8 @@ static void get_capabilities(struct scsi_cd *cd)
 {
         unsigned char *buffer;
         struct scsi_mode_data data;
-        unsigned char cmd[MAX_COMMAND_SIZE];
         struct scsi_sense_hdr sshdr;
-        unsigned int the_result;
-        int retries, rc, n;
+        int rc, n;
 
         static const char *loadmech[] =
         {
@@ -758,23 +778,8 @@ static void get_capabilities(struct scsi_cd *cd)
                 return;
         }
 
-        /* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION
-         * conditions are gone, or a timeout happens
-         */
-        retries = 0;
-        do {
-                memset((void *)cmd, 0, MAX_COMMAND_SIZE);
-                cmd[0] = TEST_UNIT_READY;
-
-                the_result = scsi_execute_req (cd->device, cmd, DMA_NONE, NULL,
-                                               0, &sshdr, SR_TIMEOUT,
-                                               MAX_RETRIES);
-
-                retries++;
-        } while (retries < 5 && 
-                 (!scsi_status_is_good(the_result) ||
-                  (scsi_sense_valid(&sshdr) &&
-                   sshdr.sense_key == UNIT_ATTENTION)));
+        /* eat unit attentions */
+        sr_test_unit_ready(cd->device, &sshdr);
 
         /* ask for mode page 0x2a */
         rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,