wlc_phy_compute_dB converts absolute power value to dB implementing a fixed point calculation for 10*log10(x). It does this by determining the most significant bit for value x. This can be done using the fls() bit operation, which has arch specific and possibly more efficient implementation.
Cc: [email protected] Cc: [email protected] Reviewed-by: Roland Vossen <[email protected]> Reviewed-by: Henry Ptasinski <[email protected]> Reviewed-by: Brett Rudley <[email protected]> Signed-off-by: Arend van Spriel <[email protected]> --- .../staging/brcm80211/brcmsmac/phy/wlc_phy_cmn.c | 19 ++++++++----------- 1 files changed, 8 insertions(+), 11 deletions(-) diff --git a/drivers/staging/brcm80211/brcmsmac/phy/wlc_phy_cmn.c b/drivers/staging/brcm80211/brcmsmac/phy/wlc_phy_cmn.c index 446dc84..6cba4df 100644 --- a/drivers/staging/brcm80211/brcmsmac/phy/wlc_phy_cmn.c +++ b/drivers/staging/brcm80211/brcmsmac/phy/wlc_phy_cmn.c @@ -18,10 +18,12 @@ #include <linux/kernel.h> #include <linux/string.h> -#include <bcmdefs.h> +#include <linux/bitops.h> #include <linux/delay.h> #include <linux/module.h> #include <linux/pci.h> + +#include <bcmdefs.h> #include <bcmnvram.h> #include <sbchipc.h> #include <bcmdevs.h> @@ -2746,20 +2748,15 @@ s8 lcnphy_gain_index_offset_for_pkt_rssi[] = { void wlc_phy_compute_dB(u32 *cmplx_pwr, s8 *p_cmplx_pwr_dB, u8 core) { - u8 shift_ct, lsb, msb, secondmsb, i; + u8 msb, secondmsb, i; u32 tmp; for (i = 0; i < core; i++) { + secondmsb = 0; tmp = cmplx_pwr[i]; - shift_ct = msb = secondmsb = 0; - while (tmp != 0) { - tmp = tmp >> 1; - shift_ct++; - lsb = (u8) (tmp & 1); - if (lsb == 1) - msb = shift_ct; - } - secondmsb = (u8) ((cmplx_pwr[i] >> (msb - 1)) & 1); + msb = fls(tmp); + if (msb) + secondmsb = (u8) ((tmp >> (--msb - 1)) & 1); p_cmplx_pwr_dB[i] = (s8) (3 * msb + 2 * secondmsb); } } -- 1.7.4.1 _______________________________________________ devel mailing list [email protected] http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
