On 05/06/10 12:29, Helmut Schaa wrote: > 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 <helmut.schaa@xxxxxxxxxxxxxx> Good catch. Acked-by: Gertjan van Wingerde <gwingerde@xxxxxxxxx> > --- > drivers/net/wireless/rt2x00/rt2800lib.c | 11 +++++++++-- > 1 files changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c > index e37bbea..f786068 100644 > --- a/drivers/net/wireless/rt2x00/rt2800lib.c > +++ b/drivers/net/wireless/rt2x00/rt2800lib.c > @@ -1415,9 +1415,16 @@ 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); -- 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
