This is a note to let you know that I've just added the patch titled
firewire: ohci: fix too-early completion of IR multichannel buffers
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
firewire-ohci-fix-too-early-completion-of-ir-multichannel-buffers.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 0c0efbacab8d70700d13301e0ae7975783c0cb0a Mon Sep 17 00:00:00 2001
From: Clemens Ladisch <[email protected]>
Date: Mon, 12 Mar 2012 21:45:47 +0100
Subject: firewire: ohci: fix too-early completion of IR multichannel buffers
From: Clemens Ladisch <[email protected]>
commit 0c0efbacab8d70700d13301e0ae7975783c0cb0a upstream.
handle_ir_buffer_fill() assumed that a completed descriptor would be
indicated by a non-zero transfer_status (as in most other descriptors).
However, this field is written by the controller as soon as (the end of)
the first packet has been written into the buffer. As a consequence, if
we happen to run into such a descriptor when the interrupt handler is
executed after such a packet has completed, the descriptor would be
taken out of the list of active descriptors as soon as the buffer had
been partially filled, so the event for the buffer being completely
filled would never be sent.
To fix this, handle descriptors only when they have been completely
filled, i.e., when res_count == 0. (This also matches the condition
that is reported by the controller with an interrupt.)
Signed-off-by: Clemens Ladisch <[email protected]>
Signed-off-by: Stefan Richter <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/firewire/ohci.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -2558,15 +2558,14 @@ static int handle_ir_buffer_fill(struct
struct iso_context *ctx =
container_of(context, struct iso_context, context);
- if (!last->transfer_status)
+ if (last->res_count != 0)
/* Descriptor(s) not done yet, stop iteration */
return 0;
if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS)
ctx->base.callback.mc(&ctx->base,
le32_to_cpu(last->data_address) +
- le16_to_cpu(last->req_count) -
- le16_to_cpu(last->res_count),
+ le16_to_cpu(last->req_count),
ctx->base.callback_data);
return 1;
Patches currently in stable-queue which might be from [email protected] are
queue-3.0/firewire-ohci-fix-too-early-completion-of-ir-multichannel-buffers.patch
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