linux-kernel - [PATCH v2] bcma: Replace mdelay with usleep_range in bcma_pmu_resources

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Date:   Sat, 27 Jan 2018 00:38:35 +0800
From:   Jia-Ju Bai <baijiaju1990@...il.com>
To:     Larry.Finger@...inger.net, kvalo@...eaurora.org, zajec5@...il.com
Cc:     linux-wireless@...r.kernel.org, linux-kernel@...r.kernel.org,
        Jia-Ju Bai <baijiaju1990@...il.com>
Subject: [PATCH v2] bcma: Replace mdelay with usleep_range in bcma_pmu_resources_init

After checking all possible call chains to bcma_pmu_resources_init() here,
my tool finds that this function is never called in atomic context,
namely never in an interrupt handler or holding a spinlock.
Thus mdelay can be replaced with usleep_range to avoid busy wait.

This is found by a static analysis tool named DCNS written by myself.

Signed-off-by: Jia-Ju Bai <baijiaju1990@...il.com>
---
v2:
* Use usleep_range(2000, 2500), instead of (1500, 2000) in v1.

---
 drivers/bcma/driver_chipcommon_pmu.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bcma/driver_chipcommon_pmu.c b/drivers/bcma/driver_chipcommon_pmu.c
index f1eb4d3..478948c 100644
--- a/drivers/bcma/driver_chipcommon_pmu.c
+++ b/drivers/bcma/driver_chipcommon_pmu.c
@@ -203,7 +203,7 @@ static void bcma_pmu_resources_init(struct bcma_drv_cc *cc)
 	 * Add some delay; allow resources to come up and settle.
 	 * Delay is required for SoC (early init).
 	 */
-	mdelay(2);
+	usleep_range(2000, 2500);
 }
 
 /* Disable to allow reading SPROM. Don't know the adventages of enabling it. */
-- 
1.7.9.5