staging: rtl8192u: Replace mdelay with usleep_range in dm_TXPowerTrackingCallback_TSSI

dm_TXPowerTrackingCallback_TSSI() is never called in atomic context.

dm_TXPowerTrackingCallback_TSSI() is only called by
dm_txpower_trackingcallback(), which is set a parameter of
INIT_DELAYED_WORK() in rtl8192_init_priv_task().

Despite never getting called from atomic context,
dm_TXPowerTrackingCallback_TSSI() calls mdelay() to busily wait.
This is not necessary and can be replaced with usleep_range() to
avoid busy waiting.

This is found by a static analysis tool named DCNS written by myself.
And I also manually check it

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/rtl8192u/r8192U_dm.c b/drivers/staging/rtl8192u/r8192U_dm.c
index e1b81d34f1ad80abc43e079a56c446b2fdb42675..e25b058dec2664045bf4b60b4717d161292c8ccb 100644 (file)
--- a/drivers/staging/rtl8192u/r8192U_dm.c
+++ b/drivers/staging/rtl8192u/r8192U_dm.c
@@ -539,13 +539,13 @@ static void dm_TXPowerTrackingCallback_TSSI(struct net_device *dev)
                rtStatus = SendTxCommandPacket(dev, &tx_cmd, 12);
                if (rtStatus == RT_STATUS_FAILURE)
                        RT_TRACE(COMP_POWER_TRACKING, "Set configuration with tx cmd queue fail!\n");
-               mdelay(1);
+               usleep_range(1000, 2000);
                /*DbgPrint("hi, vivi, strange\n");*/
                for (i = 0; i <= 30; i++) {
                        read_nic_byte(dev, 0x1ba, &Pwr_Flag);
 
                        if (Pwr_Flag == 0) {
-                               mdelay(1);
+                               usleep_range(1000, 2000);
                                continue;
                        }
                        read_nic_word(dev, 0x13c, &Avg_TSSI_Meas);