From a21c2ab4210a89a71a0a99685acf16ae126b2eee Mon Sep 17 00:00:00 2001 From: Helmut Schaa Date: Thu, 6 May 2010 12:29:04 +0200 Subject: [PATCH] rt2x00: rt2800: update initial SIFS values Currently the CCK and OFDM SIFS value is set to 32us. This value is neither used by the Ralink driver nor specified in 802.11. Instead of using 10us for CCK SIFS (as defined in 802.11) use 16us like in the Ralink drivers. And indeed using a SIFS value of 10us breaks connectivity with 11g + CTS protected connections. Add a comment to the code why we don't use 10us for CCK SIFS value. The OFDM SIFS value is set to 16us (as defined in 802.11 and also used by the Ralink drivers). Signed-off-by: Helmut Schaa Acked-by: Ivo van Doorn Acked-by: Gertjan van Wingerde Signed-off-by: John W. Linville --- drivers/net/wireless/rt2x00/rt2800lib.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c index 6d2c66d9b290..11a0d8b6235d 100644 --- a/drivers/net/wireless/rt2x00/rt2800lib.c +++ b/drivers/net/wireless/rt2x00/rt2800lib.c @@ -1414,9 +1414,16 @@ int rt2800_init_registers(struct rt2x00_dev *rt2x00dev) rt2800_register_write(rt2x00dev, EXP_ACK_TIME, 0x002400ca); + /* + * Usually the CCK SIFS time should be set to 10 and the OFDM SIFS + * time should be set to 16. However, the original Ralink driver uses + * 16 for both and indeed using a value of 10 for CCK SIFS results in + * connection problems with 11g + CTS protection. Hence, use the same + * defaults as the Ralink driver: 16 for both, CCK and OFDM SIFS. + */ rt2800_register_read(rt2x00dev, XIFS_TIME_CFG, ®); - rt2x00_set_field32(®, XIFS_TIME_CFG_CCKM_SIFS_TIME, 32); - rt2x00_set_field32(®, XIFS_TIME_CFG_OFDM_SIFS_TIME, 32); + rt2x00_set_field32(®, XIFS_TIME_CFG_CCKM_SIFS_TIME, 16); + rt2x00_set_field32(®, XIFS_TIME_CFG_OFDM_SIFS_TIME, 16); rt2x00_set_field32(®, XIFS_TIME_CFG_OFDM_XIFS_TIME, 4); rt2x00_set_field32(®, XIFS_TIME_CFG_EIFS, 314); rt2x00_set_field32(®, XIFS_TIME_CFG_BB_RXEND_ENABLE, 1);