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| author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2008-05-25 11:06:55 +0200 |
|---|---|---|
| committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2008-07-14 13:06:03 +0200 |
| commit | a7ea67823af4a7e442e92064b0fab46603a588f6 (patch) | |
| tree | f6d67468a3a363ee6753b11a4e6656b454b5fe98 /drivers/firewire/fw-transaction.c | |
| parent | 459f79235d8faa0050180c7e0c7bb4b2b52cbdfd (diff) | |
| download | lwn-a7ea67823af4a7e442e92064b0fab46603a588f6.tar.gz lwn-a7ea67823af4a7e442e92064b0fab46603a588f6.zip | |
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/fw-transaction.c')
| -rw-r--r-- | drivers/firewire/fw-transaction.c | 12 |
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; } |