From db5d247ae811f49185a71e703b65acad845e4b18 Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Thu, 24 Dec 2009 12:05:58 +0100 Subject: firewire: fix use of multiple AV/C devices, allow multiple FCP listeners Control of more than one AV/C device at once --- e.g. camcorders, tape decks, audio devices, TV tuners --- failed or worked only unreliably, depending on driver implementation. This affected kernelspace and userspace drivers alike and was caused by firewire-core's inability to accept multiple registrations of FCP listeners. The fix allows multiple address handlers to be registered for the FCP command and response registers. When a request for these registers is received, all handlers are invoked, and the Firewire response is generated by the core and not by any handler. The cdev API does not change, i.e., userspace is still expected to send a response for FCP requests; this response is silently ignored. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter (changelog, rebased, whitespace) --- drivers/firewire/core-cdev.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) (limited to 'drivers/firewire/core-cdev.c') diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c index 231e6ee5ba4..2cb22d160f6 100644 --- a/drivers/firewire/core-cdev.c +++ b/drivers/firewire/core-cdev.c @@ -601,8 +601,9 @@ static void release_request(struct client *client, struct inbound_transaction_resource *r = container_of(resource, struct inbound_transaction_resource, resource); - fw_send_response(client->device->card, r->request, - RCODE_CONFLICT_ERROR); + if (r->request) + fw_send_response(client->device->card, r->request, + RCODE_CONFLICT_ERROR); kfree(r); } @@ -645,7 +646,8 @@ static void handle_request(struct fw_card *card, struct fw_request *request, failed: kfree(r); kfree(e); - fw_send_response(card, request, RCODE_CONFLICT_ERROR); + if (request) + fw_send_response(card, request, RCODE_CONFLICT_ERROR); } static void release_address_handler(struct client *client, @@ -715,15 +717,17 @@ static int ioctl_send_response(struct client *client, void *buffer) r = container_of(resource, struct inbound_transaction_resource, resource); - if (request->length < r->length) - r->length = request->length; - - if (copy_from_user(r->data, u64_to_uptr(request->data), r->length)) { - ret = -EFAULT; - goto out; + if (r->request) { + if (request->length < r->length) + r->length = request->length; + if (copy_from_user(r->data, u64_to_uptr(request->data), + r->length)) { + ret = -EFAULT; + goto out; + } + fw_send_response(client->device->card, r->request, + request->rcode); } - - fw_send_response(client->device->card, r->request, request->rcode); out: kfree(r); -- cgit v1.2.3-70-g09d2