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authorStefan Richter <stefanr@s5r6.in-berlin.de>2008-05-25 11:06:55 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2008-07-14 13:06:03 +0200
commita7ea67823af4a7e442e92064b0fab46603a588f6 (patch)
treef6d67468a3a363ee6753b11a4e6656b454b5fe98 /drivers/firewire
parent459f79235d8faa0050180c7e0c7bb4b2b52cbdfd (diff)
downloadlinux-a7ea67823af4a7e442e92064b0fab46603a588f6.tar.bz2
firewire: don't respond to broadcast write requests
Contrary to a comment in the source, request->ack of a broadcast write request can be ACK_PENDING. Hence the existing check is insufficient. Debug dmesg before: AR spd 0 tl 00, ffc0 -> ffff, ack_pending , QW req, fffff0000234 = ffffffff AT spd 0 tl 00, ffff -> ffc0, ack_complete, W resp And the requesting node (linux1394) reports an unsolicited response. Debug dmesg after: AR spd 0 tl 00, ffc0 -> ffff, ack_pending , QW req, fffff0000234 = ffffffff Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'drivers/firewire')
-rw-r--r--drivers/firewire/fw-transaction.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/firewire/fw-transaction.c b/drivers/firewire/fw-transaction.c
index 2f11ed1acf01..40db80752272 100644
--- a/drivers/firewire/fw-transaction.c
+++ b/drivers/firewire/fw-transaction.c
@@ -55,6 +55,9 @@
#define HEADER_GET_DATA_LENGTH(q) (((q) >> 16) & 0xffff)
#define HEADER_GET_EXTENDED_TCODE(q) (((q) >> 0) & 0xffff)
+#define HEADER_DESTINATION_IS_BROADCAST(q) \
+ (((q) & HEADER_DESTINATION(0x3f)) == HEADER_DESTINATION(0x3f))
+
#define PHY_CONFIG_GAP_COUNT(gap_count) (((gap_count) << 16) | (1 << 22))
#define PHY_CONFIG_ROOT_ID(node_id) ((((node_id) & 0x3f) << 24) | (1 << 23))
#define PHY_IDENTIFIER(id) ((id) << 30)
@@ -624,12 +627,9 @@ allocate_request(struct fw_packet *p)
void
fw_send_response(struct fw_card *card, struct fw_request *request, int rcode)
{
- /*
- * Broadcast packets are reported as ACK_COMPLETE, so this
- * check is sufficient to ensure we don't send response to
- * broadcast packets or posted writes.
- */
- if (request->ack != ACK_PENDING) {
+ /* unified transaction or broadcast transaction: don't respond */
+ if (request->ack != ACK_PENDING ||
+ HEADER_DESTINATION_IS_BROADCAST(request->request_header[0])) {
kfree(request);
return;
}