Some hardware require the ieee80211 header to be aligned to a 4-byte boundary before mapping it to the DMA. Otherwise some frames (like beacons) will not be send out correctly by the device. Signed-off-by: Ivo van Doorn <IvDoorn@xxxxxxxxx> --- drivers/net/wireless/rt2x00/rt2x00queue.c | 12 ++++++++++++ 1 files changed, 12 insertions(+), 0 deletions(-) diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c index 65435c9..e67e339 100644 --- a/drivers/net/wireless/rt2x00/rt2x00queue.c +++ b/drivers/net/wireless/rt2x00/rt2x00queue.c @@ -453,9 +453,21 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb) rt2x00crypto_tx_remove_iv(skb, &txdesc); } + /* + * When DMA allocation is required we should guarentee to the + * driver that the DMA is aligned to a 4-byte boundary. + * Aligning the header to this boundary can be done by calling + * rt2x00queue_payload_align with the header length of 0. + * However some drivers require L2 padding to pad the payload + * rather then the header. This could be a requirement for + * PCI and USB devices, while header alignment only is valid + * for PCI devices. + */ if (test_bit(DRIVER_REQUIRE_L2PAD, &queue->rt2x00dev->flags)) rt2x00queue_payload_align(entry->skb, true, txdesc.header_length); + else if (test_bit(DRIVER_REQUIRE_DMA, &queue->rt2x00dev->flags)) + rt2x00queue_payload_align(entry->skb, false, 0); /* * It could be possible that the queue was corrupted and this -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
