ChangeSet 1.1730, 2004/05/17 11:38:40-07:00, [EMAIL PROTECTED]

[PATCH] USB: further fix to mdc800

I made a mistake fixing that driver. Here's the fix. Please apply soon.

  - fix race condition leading to busy waiting


 drivers/usb/image/mdc800.c |   33 +++++++++++++++++----------------
 1 files changed, 17 insertions(+), 16 deletions(-)


diff -Nru a/drivers/usb/image/mdc800.c b/drivers/usb/image/mdc800.c
--- a/drivers/usb/image/mdc800.c        Mon May 17 16:37:46 2004
+++ b/drivers/usb/image/mdc800.c        Mon May 17 16:37:46 2004
@@ -33,7 +33,7 @@
  * Fix: mdc800 used sleep_on and slept with io_lock held.
  * Converted sleep_on to waitqueues with schedule_timeout and made io_lock
  * a semaphore from a spinlock.
- * by Oliver Neukum <[EMAIL PROTECTED]>
+ * by Oliver Neukum <[EMAIL PROTECTED]>
  * (02/12/2001)
  * 
  * Identify version on module load.
@@ -41,7 +41,7 @@
  *
  * version 0.7.5
  * Fixed potential SMP races with Spinlocks.
- * Thanks to Oliver Neukum <[EMAIL PROTECTED]> who 
+ * Thanks to Oliver Neukum <[EMAIL PROTECTED]> who 
  * noticed the race conditions.
  * (30/10/2000)
  *
@@ -312,16 +312,17 @@
 static int mdc800_usb_waitForIRQ (int mode, int msec)
 {
         DECLARE_WAITQUEUE(wait, current);
+       long timeout;
 
        mdc800->camera_request_ready=1+mode;
 
        add_wait_queue(&mdc800->irq_wait, &wait);
        set_current_state(TASK_INTERRUPTIBLE);
-       if (!mdc800->irq_woken)
+       timeout = msec*HZ/1000;
+       while (!mdc800->irq_woken && timeout)
        {
-               long timeout = msec*HZ/1000;
-               while(timeout)
-                       timeout = schedule_timeout (timeout);
+               set_current_state(TASK_UNINTERRUPTIBLE);
+               timeout = schedule_timeout (timeout);
        }
         remove_wait_queue(&mdc800->irq_wait, &wait);
        set_current_state(TASK_RUNNING);
@@ -670,6 +671,7 @@
 {
        size_t left=len, sts=len; /* single transfer size */
        char* ptr=buf;
+       long timeout;
        DECLARE_WAITQUEUE(wait, current);
 
        down (&mdc800->io_lock);
@@ -717,12 +719,11 @@
                                        return len-left;
                                }
                                add_wait_queue(&mdc800->download_wait, &wait);
-                               set_current_state(TASK_INTERRUPTIBLE);
-                               if (!mdc800->downloaded)
+                               timeout = TO_DOWNLOAD_GET_READY*HZ/1000;
+                               while (!mdc800->downloaded && timeout)
                                {
-                                       long timeout = TO_DOWNLOAD_GET_READY*HZ/1000;
-                                       while(timeout)
-                                               timeout = schedule_timeout (timeout);
+                                       set_current_state(TASK_UNINTERRUPTIBLE);
+                                       timeout = schedule_timeout (timeout);
                                }
                                set_current_state(TASK_RUNNING);
                                remove_wait_queue(&mdc800->download_wait, &wait);
@@ -823,6 +824,7 @@
                if (mdc800->in_count == 8)
                {
                        int answersize;
+                       long timeout;
 
                        if (mdc800_usb_waitForIRQ (0,TO_GET_READY))
                        {
@@ -843,12 +845,11 @@
                                return -EIO;
                        }
                        add_wait_queue(&mdc800->write_wait, &wait);
-                       set_current_state(TASK_INTERRUPTIBLE);
-                       if (!mdc800->written)
+                       timeout = TO_WRITE_GET_READY*HZ/1000;
+                       while (!mdc800->written && timeout)
                        {
-                               long timeout = TO_WRITE_GET_READY*HZ/1000;
-                               while(timeout)
-                                       timeout = schedule_timeout (timeout);
+                               set_current_state(TASK_UNINTERRUPTIBLE);
+                               timeout = schedule_timeout (timeout);
                        }
                         set_current_state(TASK_RUNNING);
                        remove_wait_queue(&mdc800->write_wait, &wait);



-------------------------------------------------------
This SF.Net email is sponsored by: SourceForge.net Broadband
Sign-up now for SourceForge Broadband and get the fastest
6.0/768 connection for only $19.95/mo for the first 3 months!
http://ads.osdn.com/?ad_id%62&alloc_ida84&op=click
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel

Reply via email to