coccinielle reported the following:
./drivers/net/wireless/ath/ath5k/phy.c:1573:25-26: WARNING opportunity for swap()
while trying to fix the above warning, it reveals that ath5k_hw_get_median_noise_floor()
had open-coded sort() functionality. Since ath5k_hw_get_median_noise_floor() only
executes once every 10 seconds, any extra overhead due to sort() calling
its "compare" and "swap" functions can be ignored, so replace the
existing logic with a call to sort().
Signed-off-by: Mahmoud Maatuq <mahmoudmatook.mm@xxxxxxxxx>
Suggested-by: Jiri Slaby <jirislaby@xxxxxxxxxx>
---
changes in v2:
- update the commit message explaining why open-coded sort()
functionality is replaced with a call to sort().
- this part of updating the commit message is suggested by
Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>
changes in v1:
- replace the entire double loop with sort()
as suggested by Jiri Slaby <jirislaby@xxxxxxxxxx>
---
drivers/net/wireless/ath/ath5k/phy.c | 29 +++++++++++++---------------
1 file changed, 13 insertions(+), 16 deletions(-)
diff --git a/drivers/net/wireless/ath/ath5k/phy.c b/drivers/net/wireless/ath/ath5k/phy.c
index 5797ef9c73d7..7ee4e1616f45 100644
--- a/drivers/net/wireless/ath/ath5k/phy.c
+++ b/drivers/net/wireless/ath/ath5k/phy.c
@@ -26,6 +26,7 @@
#include <linux/delay.h>
#include <linux/slab.h>
+#include <linux/sort.h>
#include <asm/unaligned.h>
#include "ath5k.h"
@@ -1554,6 +1555,11 @@ static void ath5k_hw_update_nfcal_hist(struct ath5k_hw *ah, s16 noise_floor)
hist->nfval[hist->index] = noise_floor;
}
+static int cmps16(const void *a, const void *b)
+{
+ return *(s16 *)a - *(s16 *)b;
+}
+
/**
* ath5k_hw_get_median_noise_floor() - Get median NF from history buffer
* @ah: The &struct ath5k_hw
@@ -1561,25 +1567,16 @@ static void ath5k_hw_update_nfcal_hist(struct ath5k_hw *ah, s16 noise_floor)
static s16
ath5k_hw_get_median_noise_floor(struct ath5k_hw *ah)
{
- s16 sort[ATH5K_NF_CAL_HIST_MAX];
- s16 tmp;
- int i, j;
-
- memcpy(sort, ah->ah_nfcal_hist.nfval, sizeof(sort));
- for (i = 0; i < ATH5K_NF_CAL_HIST_MAX - 1; i++) {
- for (j = 1; j < ATH5K_NF_CAL_HIST_MAX - i; j++) {
- if (sort[j] > sort[j - 1]) {
- tmp = sort[j];
- sort[j] = sort[j - 1];
- sort[j - 1] = tmp;
- }
- }
- }
+ s16 sorted_nfval[ATH5K_NF_CAL_HIST_MAX];
+ int i;
+
+ memcpy(sorted_nfval, ah->ah_nfcal_hist.nfval, sizeof(sorted_nfval));
+ sort(sorted_nfval, ATH5K_NF_CAL_HIST_MAX, sizeof(s16), cmps16, NULL);
for (i = 0; i < ATH5K_NF_CAL_HIST_MAX; i++) {
ATH5K_DBG(ah, ATH5K_DEBUG_CALIBRATE,
- "cal %d:%d\n", i, sort[i]);
+ "cal %d:%d\n", i, sorted_nfval[i]);
}
- return sort[(ATH5K_NF_CAL_HIST_MAX - 1) / 2];
+ return sorted_nfval[(ATH5K_NF_CAL_HIST_MAX - 1) / 2];
}
/**
--
2.34.1
