firewire: fix libdc1394/FlyCap2 iso event regression

commit 0699a73af3811b66b1ab5650575acee5eea841ab upstream.

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>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 7ef316fdc4d9..ac1b43a04285 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 @@ static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg)
                         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);