RE: [PATCH] Adaptec AACRAID: convert fibctx->wait_sem to completion

[Salyzyn, Mark]

linux/completion is already included in commctrl.c, in the patch fragment it is noted two lines below the addition. Please explain in the description the need/advantages for the change from semaphore to completion.

Sincerely -- Mark Salyzyn

> -----Original Message-----
> From: Matthias Kaehlcke [mailto:matthias@xxxxxxxxxxxx]
> Sent: Wednesday, February 13, 2008 1:35 PM
> To: AACRAID; linux-scsi@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx
> Subject: [PATCH] Adaptec AACRAID: convert fibctx->wait_sem to
> completion
>
> Adaptec AACRAID driver: The semaphore fibctx->wait_sem is used for
> signalling an event. Convert it to a completion.
>
> Signed-off-by: Matthias Kaehlcke <matthias@xxxxxxxxxxxx>
>
> --
> diff --git a/drivers/scsi/aacraid/aacraid.h
> b/drivers/scsi/aacraid/aacraid.h
> index 3195d29..eef4939 100644
> --- a/drivers/scsi/aacraid/aacraid.h
> +++ b/drivers/scsi/aacraid/aacraid.h
> @@ -717,7 +717,7 @@ struct aac_fib_context {
>         u32                     unique;         // unique
> value representing this context
>         ulong                   jiffies;        // used for
> cleanup - dmb changed to ulong
>         struct list_head        next;           // used to
> link context's into a linked list
> -       struct semaphore        wait_sem;       // this is
> used to wait for the next fib to arrive.
> +       struct completion       compl;          // this is
> used to wait for the next fib to arrive.
>         int                     wait;           // Set to
> true when thread is in WaitForSingleObject
>         unsigned long           count;          // total
> number of FIBs on FibList
>         struct list_head        fib_list;       // this holds
> fibs and their attachd hw_fibs
> diff --git a/drivers/scsi/aacraid/commctrl.c
> b/drivers/scsi/aacraid/commctrl.c
> index abef051..98efda6 100644
> --- a/drivers/scsi/aacraid/commctrl.c
> +++ b/drivers/scsi/aacraid/commctrl.c
> @@ -33,6 +33,7 @@
>  #include <linux/types.h>
>  #include <linux/pci.h>
>  #include <linux/spinlock.h>
> +#include <linux/completion.h>
>  #include <linux/slab.h>
>  #include <linux/completion.h>
>  #include <linux/dma-mapping.h>
> @@ -177,9 +178,9 @@ static int open_getadapter_fib(struct
> aac_dev * dev, void __user *arg)
>                  */
>                 fibctx->unique = (u32)((ulong)fibctx & 0xFFFFFFFF);
>                 /*
> -                *      Initialize the mutex used to wait for
> the next AIF.
> +                *      Initialize the completion used to
> wait for the next AIF.
>                  */
> -               init_MUTEX_LOCKED(&fibctx->wait_sem);
> +               init_completion(&fibctx->compl);
>                 fibctx->wait = 0;
>                 /*
>                  *      Initialize the fibs and set the count
> of fibs on
> @@ -310,7 +311,7 @@ return_fib:
>                         ssleep(1);
>                 }
>                 if (f.wait) {
> -
> if(down_interruptible(&fibctx->wait_sem) < 0) {
> +
> if(wait_for_completion_interruptible(&fibctx->compl) < 0) {
>                                 status = -EINTR;
>                         } else {
>                                 /* Lock again and retry */
> diff --git a/drivers/scsi/aacraid/commsup.c
> b/drivers/scsi/aacraid/commsup.c
> index 81b3692..486bdb3 100644
> --- a/drivers/scsi/aacraid/commsup.c
> +++ b/drivers/scsi/aacraid/commsup.c
> @@ -1440,7 +1440,7 @@ int aac_check_health(struct aac_dev * aac)
>                          * Set the event to wake up the
>                          * thread that will waiting.
>                          */
> -                       up(&fibctx->wait_sem);
> +                       complete(&fibctx->compl);
>                 } else {
>                         printk(KERN_WARNING "aifd: didn't
> allocate NewFib.\n");
>                         kfree(fib);
> @@ -1671,7 +1671,7 @@ int aac_command_thread(void *data)
>                                                  * Set the
> event to wake up the
>                                                  * thread
> that is waiting.
>                                                  */
> -                                               up(&fibctx->wait_sem);
> +
> complete(&fibctx->compl);
>                                         } else {
>
> printk(KERN_WARNING "aifd: didn't allocate NewFib.\n");
>                                         }
> --
> Matthias Kaehlcke
> Linux System Developer
> Barcelona
>
>   Si deseas mantener tu libertad, debes estar preparado para
> defenderla
>                           (Richard Stallman)
>                                                                  .''`.
>     using free software / Debian GNU/Linux |
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>
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