firewire: Implement proper transaction cancelation.
Drivers such as fw-sbp2 had no way to properly cancel in-progress
transactions, which could leave a pending transaction or an unset
packet in the low-level queues after kfree'ing the containing
structure. fw_cancel_transaction() lets drivers cancel a submitted
transaction.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index 02b2b69..e6fa349 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -79,6 +79,7 @@
struct fw_ohci *ohci;
dma_addr_t descriptor_bus;
dma_addr_t buffer_bus;
+ struct fw_packet *current_packet;
struct list_head list;
@@ -489,6 +490,7 @@
ctx->descriptor_bus | z);
reg_write(ctx->ohci, control_set(ctx->regs),
CONTEXT_RUN | CONTEXT_WAKE);
+ ctx->current_packet = packet;
} else {
/* We dont return error codes from this function; all
* transmission errors are reported through the
@@ -524,6 +526,12 @@
at_context_stop(ctx);
+ /* If the head of the list isn't the packet that just got
+ * transmitted, the packet got cancelled before we finished
+ * transmitting it. */
+ if (ctx->current_packet != packet)
+ goto skip_to_next;
+
if (packet->payload_length > 0) {
dma_unmap_single(ohci->card.device, packet->payload_bus,
packet->payload_length, DMA_TO_DEVICE);
@@ -564,6 +572,7 @@
} else
complete_transmission(packet, evt - 16, &list);
+ skip_to_next:
/* If more packets are queued, set up the next one. */
if (!list_empty(&ctx->list))
at_context_setup_packet(ctx, &list);
@@ -1012,6 +1021,29 @@
at_context_transmit(&ohci->at_response_ctx, packet);
}
+static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
+{
+ struct fw_ohci *ohci = fw_ohci(card);
+ LIST_HEAD(list);
+ unsigned long flags;
+
+ spin_lock_irqsave(&ohci->lock, flags);
+
+ if (packet->ack == 0) {
+ fw_notify("cancelling packet %p (header[0]=%08x)\n",
+ packet, packet->header[0]);
+
+ complete_transmission(packet, RCODE_CANCELLED, &list);
+ }
+
+ spin_unlock_irqrestore(&ohci->lock, flags);
+
+ do_packet_callbacks(ohci, &list);
+
+ /* Return success if we actually cancelled something. */
+ return list_empty(&list) ? -ENOENT : 0;
+}
+
static int
ohci_enable_phys_dma(struct fw_card *card, int node_id, int generation)
{
@@ -1339,6 +1371,7 @@
.set_config_rom = ohci_set_config_rom,
.send_request = ohci_send_request,
.send_response = ohci_send_response,
+ .cancel_packet = ohci_cancel_packet,
.enable_phys_dma = ohci_enable_phys_dma,
.allocate_iso_context = ohci_allocate_iso_context,