The loop in usb_sg_wait() is structured in a way that makes it hard to
tell, when the loop exits, whether or not the last URB submission
succeeded. This patch (as928) changes it from a "for" loop to a
"while" loop and keeps "i" always equal to the number of successful
submissions. This fixes an off-by-one error which can show up when
the first URB submission fails.
The patch also removes a couple of lines that initialize fields which
don't need to be initialized.
Signed-off-by: Alan Stern <[EMAIL PROTECTED]>
---
Index: usb-2.6/drivers/usb/core/message.c
===================================================================
--- usb-2.6.orig/drivers/usb/core/message.c
+++ usb-2.6/drivers/usb/core/message.c
@@ -404,8 +404,6 @@ int usb_sg_init (
io->urbs [i]->complete = sg_complete;
io->urbs [i]->context = io;
- io->urbs [i]->status = -EINPROGRESS;
- io->urbs [i]->actual_length = 0;
/*
* Some systems need to revert to PIO when DMA is temporarily
@@ -499,7 +497,8 @@ void usb_sg_wait (struct usb_sg_request
/* queue the urbs. */
spin_lock_irq (&io->lock);
- for (i = 0; i < entries && !io->status; i++) {
+ i = 0;
+ while (i < entries && !io->status) {
int retval;
io->urbs [i]->dev = io->dev;
@@ -516,7 +515,6 @@ void usb_sg_wait (struct usb_sg_request
case -ENOMEM:
io->urbs[i]->dev = NULL;
retval = 0;
- i--;
yield ();
break;
@@ -527,6 +525,7 @@ void usb_sg_wait (struct usb_sg_request
* URBs are queued at once; N milliseconds?
*/
case 0:
+ ++i;
cpu_relax ();
break;
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