From 07ef0938d89b3c5af9d3ff23e482b26202bd012c Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Mon, 12 Mar 2012 21:45:47 +0100 Subject: firewire: ohci: fix too-early completion of IR multichannel buffers 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 Signed-off-by: Stefan Richter Signed-off-by: Greg Kroah-Hartman --- drivers/firewire/ohci.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'drivers/firewire') diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 7f97c3097900..271fc518dec5 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -2558,15 +2558,14 @@ static int handle_ir_buffer_fill(struct context *context, 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; -- cgit v1.2.1