diff options
| author | Jay Fenlason <fenlason@redhat.com> | 2009-12-11 14:23:58 -0500 |
|---|---|---|
| committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2009-12-11 21:43:45 +0100 |
| commit | 8c0c0cc2d9f4c523fde04bdfe41e4380dec8ee54 (patch) | |
| tree | eeb3a432eab9e357b332366fe7719fa932e29b88 | |
| parent | af0940dac37545b1e7900b19c464fb6367d3f82f (diff) | |
firewire: ohci: handle receive packets with a data length of zero
Queueing to receive an ISO packet with a payload length of zero
silently does nothing in dualbuffer mode, and crashes the kernel in
packet-per-buffer mode. Return an error in dualbuffer mode, because
the DMA controller won't let us do what we want, and work correctly in
packet-per-buffer mode.
Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cc: stable@kernel.org
| -rw-r--r-- | drivers/firewire/ohci.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index a71477541dc..553c74e1e4e 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -2189,6 +2189,13 @@ static int ohci_queue_iso_receive_dualbuffer(struct fw_iso_context *base, page = payload >> PAGE_SHIFT; offset = payload & ~PAGE_MASK; rest = p->payload_length; + /* + * The controllers I've tested have not worked correctly when + * second_req_count is zero. Rather than do something we know won't + * work, return an error + */ + if (rest == 0) + return -EINVAL; /* FIXME: make packet-per-buffer/dual-buffer a context option */ while (rest > 0) { @@ -2242,7 +2249,7 @@ static int ohci_queue_iso_receive_packet_per_buffer(struct fw_iso_context *base, unsigned long payload) { struct iso_context *ctx = container_of(base, struct iso_context, base); - struct descriptor *d = NULL, *pd = NULL; + struct descriptor *d, *pd; struct fw_iso_packet *p = packet; dma_addr_t d_bus, page_bus; u32 z, header_z, rest; @@ -2280,8 +2287,9 @@ static int ohci_queue_iso_receive_packet_per_buffer(struct fw_iso_context *base, d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d))); rest = payload_per_buffer; + pd = d; for (j = 1; j < z; j++) { - pd = d + j; + pd++; pd->control = cpu_to_le16(DESCRIPTOR_STATUS | DESCRIPTOR_INPUT_MORE); |