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: devel@xxxxxxxxxxxxxxxxxxxxxx
Cc: linux-wireless@xxxxxxxxxxxxxxx
Reviewed-by: Roland Vossen <rvossen@xxxxxxxxxxxxx>
Reviewed-by: Henry Ptasinski <henryp@xxxxxxxxxxxx>
Reviewed-by: Brett Rudley <brudley@xxxxxxxxxxxx>
Signed-off-by: Arend van Spriel <arend@xxxxxxxxxxxx>
---
.../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
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