rtl8187: add short slot handling for 8187B
This change adds short slot handling for 8187B variant of rtl8187 chips.
Some things to note about changes done:
* Values used are chosen to met 802.11-2007 spec. This raised a question
about SIFS value used with 8187L: 0x22 (34) doesn't match any spec
value. For now just don't change 8187L, but is something to be
looked at.
* On 8187B, the location of EIFS register is at the same place as BRSR+1
of struct rtl818x_csr. Unfortunately there is no clean way to
accomodate 8187B differences currently, just use address of BRSR+1 and
comment about it. The same thing happens for Ack timeout register,
that is on CARRIER_SENSE_COUNTER location of 8187L. The eifs and ack
timeout values are in units of 4us. All these registers information
was gathered from references being the vendor gpl driver and 8180
datasheet, unfortunately there is no information about this on 8187B
datasheet. Also the ack timeout value was inspired by the same
calculation as done on rt2x00.
Signed-off-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2 files changed