netdev - [PATCH 2/2] isdn: hisax_fcpcipnp: Replace mdelay with usleep_range in fcpcipnp

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Date:   Wed, 11 Apr 2018 11:33:51 +0800
From:   Jia-Ju Bai <baijiaju1990@...il.com>
To:     isdn@...ux-pingi.de, davem@...emloft.net,
        stephen@...workplumber.org, johannes.berg@...el.com,
        arvind.yadav.cs@...il.com
Cc:     netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        Jia-Ju Bai <baijiaju1990@...il.com>
Subject: [PATCH 2/2] isdn: hisax_fcpcipnp: Replace mdelay with usleep_range in fcpcipnp_setup

fcpcipnp_setup() is never called in atomic context.

The call chain ending up at fcpcipnp_setup() is:
[1] fcpcipnp_setup() <- fcpnp_probe()

fcpnp_probe() is set as ".probe" in struct pnp_driver.
This function is not called in atomic context.

Despite never getting called from atomic context, fcpcipnp_setup()
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@...il.com>
---
 drivers/isdn/hisax/hisax_fcpcipnp.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/isdn/hisax/hisax_fcpcipnp.c b/drivers/isdn/hisax/hisax_fcpcipnp.c
index e4f7573..06068a42 100644
--- a/drivers/isdn/hisax/hisax_fcpcipnp.c
+++ b/drivers/isdn/hisax/hisax_fcpcipnp.c
@@ -772,11 +772,11 @@ static int fcpcipnp_setup(struct fritz_adapter *adapter)
 
 	// Reset
 	outb(0, adapter->io + AVM_STATUS0);
-	mdelay(10);
+	usleep_range(10000, 11000);
 	outb(AVM_STATUS0_RESET, adapter->io + AVM_STATUS0);
-	mdelay(10);
+	usleep_range(10000, 11000);
 	outb(0, adapter->io + AVM_STATUS0);
-	mdelay(10);
+	usleep_range(10000, 11000);
 
 	switch (adapter->type) {
 	case AVM_FRITZ_PCIV2:
-- 
1.9.1