From 7a4a77b7771164d61ce702a588067d1e1d66db7c Mon Sep 17 00:00:00 2001 From: Gertjan van Wingerde Date: Wed, 30 Dec 2009 11:36:30 +0100 Subject: [PATCH] rt2x00: Properly request tx headroom for alignment operations. Current rt2x00 drivers may result in a "ieee80211_tx_status: headroom too small" error message when a frame needs to be properly aligned before transmitting it. This is because the space needed to ensure proper alignment isn't requested from mac80211. Fix this by adding sufficient amount of alignment space to the amount of headroom requested for TX frames. Reported-by: David Ellingsworth Signed-off-by: Gertjan van Wingerde Acked-by: Ivo van Doorn Signed-off-by: John W. Linville --- drivers/net/wireless/rt2x00/rt2x00.h | 6 ++++++ drivers/net/wireless/rt2x00/rt2x00dev.c | 12 +++++++++++- 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h index 4d841c0..dcfc8c2 100644 --- a/drivers/net/wireless/rt2x00/rt2x00.h +++ b/drivers/net/wireless/rt2x00/rt2x00.h @@ -113,6 +113,12 @@ ( ((unsigned long)((__skb)->data + (__header))) & 3 ) /* + * Constants for extra TX headroom for alignment purposes. + */ +#define RT2X00_ALIGN_SIZE 4 /* Only whole frame needs alignment */ +#define RT2X00_L2PAD_SIZE 8 /* Both header & payload need alignment */ + +/* * Standard timing and size defines. * These values should follow the ieee80211 specifications. */ diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c index 06c43ca..265e66d 100644 --- a/drivers/net/wireless/rt2x00/rt2x00dev.c +++ b/drivers/net/wireless/rt2x00/rt2x00dev.c @@ -686,7 +686,17 @@ static int rt2x00lib_probe_hw(struct rt2x00_dev *rt2x00dev) /* * Initialize extra TX headroom required. */ - rt2x00dev->hw->extra_tx_headroom = rt2x00dev->ops->extra_tx_headroom; + rt2x00dev->hw->extra_tx_headroom = + max_t(unsigned int, IEEE80211_TX_STATUS_HEADROOM, + rt2x00dev->ops->extra_tx_headroom); + + /* + * Take TX headroom required for alignment into account. + */ + if (test_bit(DRIVER_REQUIRE_L2PAD, &rt2x00dev->flags)) + rt2x00dev->hw->extra_tx_headroom += RT2X00_L2PAD_SIZE; + else if (test_bit(DRIVER_REQUIRE_DMA, &rt2x00dev->flags)) + rt2x00dev->hw->extra_tx_headroom += RT2X00_ALIGN_SIZE; /* * Register HW. -- 2.7.4