[kernel] Apply patch to fix uvcvideo crash (rhbz 836742)

[Josh Boyer]

commit 9b66eee4c585152d045ca177f2577590f13a70e1
Author: Josh Boyer <jwboyer at redhat.com>
Date:   Thu Jul 26 10:17:19 2012 -0400

    Apply patch to fix uvcvideo crash (rhbz 836742)

 kernel.spec                                        |    7 ++++
 ...sed-field-when-recycling-erroneous-buffer.patch |   36 ++++++++++++++++++++
 2 files changed, 43 insertions(+), 0 deletions(-)
---
diff --git a/kernel.spec b/kernel.spec
index 0ed9aac..06b74ed 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -745,6 +745,9 @@ Patch22051: crypto-aesni-intel-fix-wrong-kfree-pointer.patch
 #rhbz 772730
 Patch22058: ACPI-AC-check-the-return-value-of-power_supply_register.patch
 
+#rhbz 836742
+Patch22059: uvcvideo-Reset-bytesused-field-when-recycling-erroneous-buffer.patch
+
 # END OF PATCH DEFINITIONS
 
 %endif
@@ -1435,6 +1438,9 @@ ApplyPatch crypto-aesni-intel-fix-wrong-kfree-pointer.patch
 #rhbz 772730
 ApplyPatch ACPI-AC-check-the-return-value-of-power_supply_register.patch
 
+#rhbz 836742
+ApplyPatch uvcvideo-Reset-bytesused-field-when-recycling-erroneous-buffer.patch
+
 # END OF PATCH APPLICATIONS
 
 %endif
@@ -2293,6 +2299,7 @@ fi
 #                 ||     ||
 %changelog
 * Thu Jul 26 2012 Josh Boyer <jwboyer at redhat.com>
+- Apply patch to fix uvcvideo crash (rhbz 836742)
 - Enable Intel MEI driver (rhbz 842444)
 
 * Wed Jul 25 2012 Justin M. Forbes <jforbes at redhat.com> - 3.6.0-0.rc0.git2.1
diff --git a/uvcvideo-Reset-bytesused-field-when-recycling-erroneous-buffer.patch b/uvcvideo-Reset-bytesused-field-when-recycling-erroneous-buffer.patch
new file mode 100644
index 0000000..6606b7d
--- /dev/null
+++ b/uvcvideo-Reset-bytesused-field-when-recycling-erroneous-buffer.patch
@@ -0,0 +1,36 @@
+From 3771973542a4807b251352253ed22c50e688e573 Mon Sep 17 00:00:00 2001
+From: Jayakrishnan Memana <jayakrishnan.memana at maxim-ic.com>
+Date: Sun, 15 Jul 2012 15:54:03 +0200
+Subject: [PATCH] uvcvideo: Reset the bytesused field when recycling an erroneous buffer
+
+Buffers marked as erroneous are recycled immediately by the driver if
+the nodrop module parameter isn't set. The buffer payload size is reset
+to 0, but the buffer bytesused field isn't. This results in the buffer
+being immediately considered as complete, leading to an infinite loop in
+interrupt context.
+
+Fix the problem by resetting the bytesused field when recycling the
+buffer.
+
+Cc: <stable at vger.kernel.org>
+Signed-off-by: Jayakrishnan Memana <jayakrishnan.memana at maxim-ic.com>
+Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
+---
+ drivers/media/video/uvc/uvc_queue.c |    1 +
+ 1 files changed, 1 insertions(+), 0 deletions(-)
+
+diff --git a/drivers/media/video/uvc/uvc_queue.c b/drivers/media/video/uvc/uvc_queue.c
+index 9288fbd..5577381 100644
+--- a/drivers/media/video/uvc/uvc_queue.c
++++ b/drivers/media/video/uvc/uvc_queue.c
+@@ -338,6 +338,7 @@ struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
+ 	if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) {
+ 		buf->error = 0;
+ 		buf->state = UVC_BUF_STATE_QUEUED;
++		buf->bytesused = 0;
+ 		vb2_set_plane_payload(&buf->buf, 0, 0);
+ 		return buf;
+ 	}
+-- 
+1.7.2.5
+