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ath5k: Optimize ath5k_cw_validate 

Optimize ath5k_cw_validate by using the classic (X & (X - 1)) == 0
check to see if a number is power of 2.

v2: Use functions from log2.h instead

Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Nick Kossifidis 2011-11-25 20:40:31 +02:00 committed by John W. Linville
parent b4cfb5d574
commit 9a39169105
1 changed files with 13 additions and 4 deletions
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17
drivers/net/wireless/ath/ath5k/qcu.c
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@ -23,6 +23,7 @@ Queue Control Unit, DCF Control Unit Functions
#include "ath5k.h"
#include "reg.h"
#include "debug.h"
#include <linux/log2.h>
/**
* DOC: Queue Control Unit (QCU)/DCF Control Unit (DCU) functions
@ -108,13 +109,21 @@ ath5k_hw_release_tx_queue(struct ath5k_hw *ah, unsigned int queue)
static u16
ath5k_cw_validate(u16 cw_req)
{
u32 cw = 1;
cw_req = min(cw_req, (u16)1023);
while (cw < cw_req)
cw = (cw << 1) | 1;
/* Check if cw_req + 1 a power of 2 */
if (is_power_of_2(cw_req + 1))
return cw_req;
return cw;
/* Check if cw_req is a power of 2 */
if (is_power_of_2(cw_req))
return cw_req - 1;
/* If none of the above is correct
* find the closest power of 2 */
cw_req = (u16) roundup_pow_of_two(cw_req) - 1;
return cw_req;
}
/**