[SCSI] aic7xxx: semaphore to completion conversion

On Tue, Jan 31, 2006 at 06:20:18PM +0100, Christoph Hellwig wrote:
> switch eh_sem to a completion.  due to wait_for_completion_timeout this
> also nicely simplifies the code.  Unfortunately it's untested, so if
> someone with the hardware could give it a try that would be nice.  Once
> it works the same thing can be applied to aic79xx.

New version that switches to the common onstack completion and just a
pointer in the platform_data struct idiom.  This gets rid of all the
flags fiddling.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 12 insertions, 38 deletions

diff --git a/drivers/scsi/aic7xxx/aic7xxx_osm.c b/drivers/scsi/aic7xxx/aic7xxx_osm.c
index 051970efba68..2c801672d8bb 100644
--- a/drivers/scsi/aic7xxx/aic7xxx_osm.c
+++ b/drivers/scsi/aic7xxx/aic7xxx_osm.c
@@ -373,7 +373,6 @@ static void ahc_linux_handle_scsi_status(struct ahc_softc *,
                                          struct scb *);
 static void ahc_linux_queue_cmd_complete(struct ahc_softc *ahc,
                                          struct scsi_cmnd *cmd);
-static void ahc_linux_sem_timeout(u_long arg);
 static void ahc_linux_freeze_simq(struct ahc_softc *ahc);
 static void ahc_linux_release_simq(struct ahc_softc *ahc);
 static int  ahc_linux_queue_recovery_cmd(struct scsi_cmnd *cmd, scb_flag flag);
@@ -1193,7 +1192,6 @@ ahc_platform_alloc(struct ahc_softc *ahc, void *platform_arg)
         memset(ahc->platform_data, 0, sizeof(struct ahc_platform_data));
         ahc->platform_data->irq = AHC_LINUX_NOIRQ;
         ahc_lockinit(ahc);
-        init_MUTEX_LOCKED(&ahc->platform_data->eh_sem);
         ahc->seltime = (aic7xxx_seltime & 0x3) << 4;
         ahc->seltime_b = (aic7xxx_seltime & 0x3) << 4;
         if (aic7xxx_pci_parity == 0)
@@ -1830,10 +1828,9 @@ ahc_done(struct ahc_softc *ahc, struct scb *scb)
                 if (ahc_get_transaction_status(scb) == CAM_BDR_SENT
                  || ahc_get_transaction_status(scb) == CAM_REQ_ABORTED)
                         ahc_set_transaction_status(scb, CAM_CMD_TIMEOUT);
-                if ((ahc->platform_data->flags & AHC_UP_EH_SEMAPHORE) != 0) {
-                        ahc->platform_data->flags &= ~AHC_UP_EH_SEMAPHORE;
-                        up(&ahc->platform_data->eh_sem);
-                }
+
+                if (ahc->platform_data->eh_done)
+                        complete(ahc->platform_data->eh_done);
         }
 
         ahc_free_scb(ahc, scb);
@@ -2040,22 +2037,6 @@ ahc_linux_queue_cmd_complete(struct ahc_softc *ahc, struct scsi_cmnd *cmd)
 }
 
 static void
-ahc_linux_sem_timeout(u_long arg)
-{
-        struct  ahc_softc *ahc;
-        u_long  s;
-
-        ahc = (struct ahc_softc *)arg;
-
-        ahc_lock(ahc, &s);
-        if ((ahc->platform_data->flags & AHC_UP_EH_SEMAPHORE) != 0) {
-                ahc->platform_data->flags &= ~AHC_UP_EH_SEMAPHORE;
-                up(&ahc->platform_data->eh_sem);
-        }
-        ahc_unlock(ahc, &s);
-}
-
-static void
 ahc_linux_freeze_simq(struct ahc_softc *ahc)
 {
         unsigned long s;
@@ -2355,25 +2336,21 @@ done:
         if (paused)
                 ahc_unpause(ahc);
         if (wait) {
-                struct timer_list timer;
-                int ret;
+                DECLARE_COMPLETION(done);
 
-                ahc->platform_data->flags |= AHC_UP_EH_SEMAPHORE;
+                ahc->platform_data->eh_done = &done;
                 ahc_unlock(ahc, &flags);
 
-                init_timer(&timer);
-                timer.data = (u_long)ahc;
-                timer.expires = jiffies + (5 * HZ);
-                timer.function = ahc_linux_sem_timeout;
-                add_timer(&timer);
                 printf("Recovery code sleeping\n");
-                down(&ahc->platform_data->eh_sem);
-                printf("Recovery code awake\n");
-                ret = del_timer_sync(&timer);
-                if (ret == 0) {
+                if (!wait_for_completion_timeout(&done, 5 * HZ)) {
+                        ahc_lock(ahc, &flags);
+                        ahc->platform_data->eh_done = NULL;
+                        ahc_unlock(ahc, &flags);
+
                         printf("Timer Expired\n");
                         retval = FAILED;
                 }
+                printf("Recovery code awake\n");
         } else
                 ahc_unlock(ahc, &flags);
         return (retval);
diff --git a/drivers/scsi/aic7xxx/aic7xxx_osm.h b/drivers/scsi/aic7xxx/aic7xxx_osm.h
index e0edacae895f..a20b08c9ff15 100644
--- a/drivers/scsi/aic7xxx/aic7xxx_osm.h
+++ b/drivers/scsi/aic7xxx/aic7xxx_osm.h
@@ -369,15 +369,12 @@ struct ahc_platform_data {
 
         spinlock_t               spin_lock;
         u_int                    qfrozen;
-        struct semaphore         eh_sem;
+        struct completion       *eh_done;
         struct Scsi_Host        *host;          /* pointer to scsi host */
 #define AHC_LINUX_NOIRQ ((uint32_t)~0)
         uint32_t                 irq;           /* IRQ for this adapter */
         uint32_t                 bios_address;
         uint32_t                 mem_busaddr;   /* Mem Base Addr */
-
-#define AHC_UP_EH_SEMAPHORE      0x1
-        uint32_t                 flags;
 };
 
 /************************** OS Utility Wrappers *******************************/