firewire: Don't touch DMA descriptors after appending.

When a DMA descriptor is appended to the context we sync it for
DMA and the device might potentially read it immediately.  So,
we can't set the IRQ bits in the descriptor after appending.

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 9b9ea0f3c4169424f9ab100574a80be3c1bba1af..18769d906ca91f6228deb5771e928a952e936a0f 100644 (file)
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -1621,15 +1621,15 @@ ohci_queue_iso_receive_dualbuffer(struct fw_iso_context *base,
                page_bus = page_private(buffer->pages[page]);
                db->second_buffer = cpu_to_le32(page_bus + offset);
 
+               if (p->interrupt && length == rest)
+                       db->control |= cpu_to_le16(descriptor_irq_always);
+
                context_append(&ctx->context, d, z, header_z);
                offset = (offset + length) & ~PAGE_MASK;
                rest -= length;
                page++;
        }
 
-       if (p->interrupt)
-               db->control |= cpu_to_le16(descriptor_irq_always);
-
        return 0;
 }
  
@@ -1668,6 +1668,9 @@ ohci_queue_iso_receive_bufferfill(struct fw_iso_context *base,
                d->req_count = cpu_to_le16(length);
                d->res_count = cpu_to_le16(length);
 
+               if (packet->interrupt && length == rest)
+                       d->control |= cpu_to_le16(descriptor_irq_always);
+
                context_append(&ctx->context, d, 1, 0);
 
                offset = (offset + length) & ~PAGE_MASK;
@@ -1675,9 +1678,6 @@ ohci_queue_iso_receive_bufferfill(struct fw_iso_context *base,
                page++;
        }
 
-       if (packet->interrupt)
-               d->control |= cpu_to_le16(descriptor_irq_always);
-
        return 0;
 }