firewire: fix libdc1394/FlyCap2 iso event regression
Commit 18d627113b83 (firewire: prevent dropping of completed iso packet
header data) was intended to be an obvious bug fix, but libdc1394 and
FlyCap2 depend on the old behaviour by ignoring all returned information
and thus not noticing that not all packets have been received yet. The
result was that the video frame buffers would be saved before they
contained the correct data.
Reintroduce the old behaviour for old clients.
Tested-by: Stepan Salenikovich <stepan.salenikovich@gmail.com>
Tested-by: Josep Bosch <jep250@gmail.com>
Cc: <stable@vger.kernel.org> # 3.4+
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 7ef316f..ac1b43a 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -54,6 +54,7 @@
#define FW_CDEV_KERNEL_VERSION 5
#define FW_CDEV_VERSION_EVENT_REQUEST2 4
#define FW_CDEV_VERSION_ALLOCATE_REGION_END 4
+#define FW_CDEV_VERSION_AUTO_FLUSH_ISO_OVERFLOW 5
struct client {
u32 version;
@@ -1005,6 +1006,8 @@
a->channel, a->speed, a->header_size, cb, client);
if (IS_ERR(context))
return PTR_ERR(context);
+ if (client->version < FW_CDEV_VERSION_AUTO_FLUSH_ISO_OVERFLOW)
+ context->drop_overflow_headers = true;
/* We only support one context at this time. */
spin_lock_irq(&client->lock);
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 9e1db64..afb701e 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -2749,8 +2749,11 @@
{
u32 *ctx_hdr;
- if (ctx->header_length + ctx->base.header_size > PAGE_SIZE)
+ if (ctx->header_length + ctx->base.header_size > PAGE_SIZE) {
+ if (ctx->base.drop_overflow_headers)
+ return;
flush_iso_completions(ctx);
+ }
ctx_hdr = ctx->header + ctx->header_length;
ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]);
@@ -2910,8 +2913,11 @@
sync_it_packet_for_cpu(context, d);
- if (ctx->header_length + 4 > PAGE_SIZE)
+ if (ctx->header_length + 4 > PAGE_SIZE) {
+ if (ctx->base.drop_overflow_headers)
+ return 1;
flush_iso_completions(ctx);
+ }
ctx_hdr = ctx->header + ctx->header_length;
ctx->last_timestamp = le16_to_cpu(last->res_count);