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authorJay Fenlason <fenlason@redhat.com>2009-12-11 14:23:58 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2009-12-18 14:02:57 -0800
commite39b7b492b646e803941117e5d879e49f40bb92f (patch)
tree37c50d041a02ec9de611610f549859c38ecf5ea6 /drivers/firewire
parentbe58b8712a2309b71d1c99ae648bca2d34c55781 (diff)
firewire: ohci: handle receive packets with a data length of zero
commit 8c0c0cc2d9f4c523fde04bdfe41e4380dec8ee54 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/firewire')
-rw-r--r--drivers/firewire/ohci.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 94260aa76aa..1e504de739e 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -2209,6 +2209,13 @@ 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) {
@@ -2262,7 +2269,7 @@ 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;
@@ -2300,8 +2307,9 @@ 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);