[SCSI] aha152x: Fix check_condition code-path

check_condition code-path was similar but more
complicated to Reset. It went like this:

  1. extra space was allocated at aha152x_scdata for mirroring
    scsi_cmnd members.
  2. At aha152x_internal_queue() every not check_condition
    (REQUEST_SENSE) command was copied to above members in
    case of error.
  3. At busfree_run() in the DONE_CS phase if a Status of
    SAM_STAT_CHECK_CONDITION was detected. The command was
    re-queued Internally using aha152x_internal_queue(,,check_condition,)
    The old command members are over written with the
    REQUEST_SENSE info.
  4. At busfree_run() in the DONE_CS phase again. If it is a
    check_condition command, info was restored from mirror
    made at first call to aha152x_internal_queue() (see 2)
    and the command is completed.

What I did is:

  1. Allocate less space in aha152x_scdata only for the 16-byte
    original command. (which is actually not needed by scsi-ml
    anymore at this stage. But this is to much knowledge of scsi-ml)
  2. If Status == SAM_STAT_CHECK_CONDITION, then like before
     re-queue a REQUEST_SENSE command. But only now save original
     command members. (Less of them)
  3. In aha152x_internal_queue(), just like for Reset, use the
    check_condition hint to set differently the working members.
    execute the command.
  4. At busfree_run() in the DONE_CS phase again. restore needed
     members.

While at it. This patch fixes a BUG. Old code when sending
a REQUEST_SENSE for a failed command. Would than return with
cmd->resid == 0 which was the status of the REQUEST_SENSE.
The failing command resid was lost. And when would resid
be interesting if not on a failing command?

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 27 insertions, 28 deletions

diff --git a/drivers/scsi/aha152x.c b/drivers/scsi/aha152x.c
index d7ca86f9d1f2..cf49ed584762 100644
--- a/drivers/scsi/aha152x.c
+++ b/drivers/scsi/aha152x.c
@@ -552,14 +552,11 @@ struct aha152x_hostdata {
 struct aha152x_scdata {
         Scsi_Cmnd *next;        /* next sc in queue */
         struct completion *done;/* semaphore to block on */
-        unsigned char cmd_len;
-        unsigned char cmnd[MAX_COMMAND_SIZE];
-        unsigned short use_sg;
-        unsigned request_bufflen;
-        void *request_buffer;
+        unsigned char aha_orig_cmd_len;
+        unsigned char aha_orig_cmnd[MAX_COMMAND_SIZE];
+        int aha_orig_resid;
 };
 
-
 /* access macros for hostdata */
 
 #define HOSTDATA(shpnt)         ((struct aha152x_hostdata *) &shpnt->hostdata)
@@ -997,20 +994,11 @@ static int aha152x_internal_queue(Scsi_Cmnd *SCpnt, struct completion *complete,
                         return FAILED;
                 }
         } else {
-                struct aha152x_scdata *sc;
-
                 SCpnt->host_scribble = kmalloc(sizeof(struct aha152x_scdata), GFP_ATOMIC);
                 if(SCpnt->host_scribble==0) {
                         printk(ERR_LEAD "allocation failed\n", CMDINFO(SCpnt));
                         return FAILED;
                 }
-
-                sc = SCDATA(SCpnt);
-                memcpy(sc->cmnd, SCpnt->cmnd, sizeof(sc->cmnd));
-                sc->request_buffer  = SCpnt->request_buffer;
-                sc->request_bufflen = SCpnt->request_bufflen;
-                sc->use_sg          = SCpnt->use_sg;
-                sc->cmd_len         = SCpnt->cmd_len;
         }
 
         SCNEXT(SCpnt)           = NULL;
@@ -1023,10 +1011,16 @@ static int aha152x_internal_queue(Scsi_Cmnd *SCpnt, struct completion *complete,
            SCp.buffers_residual : left buffers in list
            SCp.phase            : current state of the command */
 
-        if(phase & resetting) {
-                SCpnt->SCp.ptr           = NULL;
-                SCpnt->SCp.this_residual = 0;
-                SCpnt->resid             = 0;
+        if (phase & (check_condition|resetting)) {
+                if (phase & check_condition) {
+                        SCpnt->SCp.ptr           = SCpnt->sense_buffer;
+                        SCpnt->SCp.this_residual = sizeof(SCpnt->sense_buffer);
+                        SCpnt->resid             = sizeof(SCpnt->sense_buffer);
+                } else {
+                        SCpnt->SCp.ptr           = NULL;
+                        SCpnt->SCp.this_residual = 0;
+                        SCpnt->resid             = 0;
+                }
                 SCpnt->SCp.buffer           = NULL;
                 SCpnt->SCp.buffers_residual = 0;
         } else {
@@ -1568,11 +1562,9 @@ static void busfree_run(struct Scsi_Host *shpnt)
 #endif
 
                         /* restore old command */
-                        memcpy(cmd->cmnd, sc->cmnd, sizeof(sc->cmnd));
-                        cmd->request_buffer  = sc->request_buffer;
-                        cmd->request_bufflen = sc->request_bufflen;
-                        cmd->use_sg          = sc->use_sg;
-                        cmd->cmd_len         = sc->cmd_len;
+                        memcpy(cmd->cmnd, sc->aha_orig_cmnd, sizeof(cmd->cmnd));
+                        cmd->cmd_len = sc->aha_orig_cmd_len;
+                        cmd->resid = sc->aha_orig_resid;
 
                         cmd->SCp.Status = SAM_STAT_CHECK_CONDITION;
 
@@ -1588,12 +1580,22 @@ static void busfree_run(struct Scsi_Host *shpnt)
 #endif
 
                         if(!(DONE_SC->SCp.phase & not_issued)) {
+                                struct aha152x_scdata *sc;
                                 Scsi_Cmnd *ptr = DONE_SC;
                                 DONE_SC=NULL;
 #if 0
                                 DPRINTK(debug_eh, ERR_LEAD "requesting sense\n", CMDINFO(ptr));
 #endif
 
+                                /* save old command */
+                                sc = SCDATA(ptr);
+                                /* It was allocated in aha152x_internal_queue? */
+                                BUG_ON(!sc);
+                                memcpy(sc->aha_orig_cmnd, ptr->cmnd,
+                                                            sizeof(ptr->cmnd));
+                                sc->aha_orig_cmd_len = ptr->cmd_len;
+                                sc->aha_orig_resid = ptr->resid;
+
                                 ptr->cmnd[0]         = REQUEST_SENSE;
                                 ptr->cmnd[1]         = 0;
                                 ptr->cmnd[2]         = 0;
@@ -1601,10 +1603,7 @@ static void busfree_run(struct Scsi_Host *shpnt)
                                 ptr->cmnd[4]         = sizeof(ptr->sense_buffer);
                                 ptr->cmnd[5]         = 0;
                                 ptr->cmd_len         = 6;
-                                ptr->use_sg          = 0; 
-                                ptr->request_buffer  = ptr->sense_buffer;
-                                ptr->request_bufflen = sizeof(ptr->sense_buffer);
-                        
+
                                 DO_UNLOCK(flags);
                                 aha152x_internal_queue(ptr, NULL, check_condition, ptr->scsi_done);
                                 DO_LOCK(flags);