openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

rt2x00: rt2800lib: optimize frequency offset adjustment 

Don't write the new value into the register if it is
the same as the old value to avoid unncessary USB bus
traffic with USB devices. The change also saves a few
cycle on MMIO based devices.

Based on the DPO_RT5572_LinuxSTA_2.6.0.1_20120629
driver.

Reference:
  RTMPAdjustFrequencyOffset function in common/rt_rf.c

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Gabor Juhos 2013-08-17 14:09:29 +02:00 committed by John W. Linville
parent c1fada4e5e
commit 6af1bdccab
1 changed files with 6 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
drivers/net/wireless/rt2x00/rt2800lib.c
View File

@ -2497,13 +2497,18 @@ static void rt2800_config_channel_rf3053(struct rt2x00_dev *rt2x00dev,
static void rt2800_adjust_freq_offset(struct rt2x00_dev *rt2x00dev)
{
u8 freq_offset;
u8 rfcsr;
u8 rfcsr, prev_rfcsr;
freq_offset = rt2x00_get_field8(rt2x00dev->freq_offset, RFCSR17_CODE);
freq_offset = min_t(u8, freq_offset, FREQ_OFFSET_BOUND);
rt2800_rfcsr_read(rt2x00dev, 17, &rfcsr);
prev_rfcsr = rfcsr;
rt2x00_set_field8(&rfcsr, RFCSR17_CODE, freq_offset);
if (rfcsr == prev_rfcsr)
return;
rt2800_rfcsr_write(rt2x00dev, 17, rfcsr);
}