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From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: davem@davemloft.net, stephen@networkplumber.org,
	johannes.berg@intel.com, arvind.yadav.cs@gmail.com,
	dhowells@redhat.com
Cc: netdev@vger.kernel.org, linux-parisc@vger.kernel.org,
	linux-kernel@vger.kernel.org, Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH v2] dec: tulip: de4x5: Replace mdelay with usleep_range in de4x5_hw_init
Date: Wed, 11 Apr 2018 23:39:42 +0800	[thread overview]
Message-ID: <1523461182-5897-1-git-send-email-baijiaju1990@gmail.com> (raw)

de4x5_hw_init() is never called in atomic context.

de4x5_hw_init() is only called by de4x5_pci_probe(), which is only 
set as ".probe" in struct pci_driver.

Despite never getting called from atomic context, de4x5_hw_init() 
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>
---
v2:
* Use usleep_range() to correct usleep() in v1.
	
---
 drivers/net/ethernet/dec/tulip/de4x5.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/dec/tulip/de4x5.c b/drivers/net/ethernet/dec/tulip/de4x5.c
index 0affee9..3fb0119 100644
--- a/drivers/net/ethernet/dec/tulip/de4x5.c
+++ b/drivers/net/ethernet/dec/tulip/de4x5.c
@@ -1107,7 +1107,7 @@ static int (*dc_infoblock[])(struct net_device *dev, u_char, u_char *) = {
 	pdev = to_pci_dev (gendev);
 	pci_write_config_byte(pdev, PCI_CFDA_PSM, WAKEUP);
     }
-    mdelay(10);
+    usleep_range(10000, 11000);
 
     RESET_DE4X5;
 
-- 
1.9.1

             reply	other threads:[~2018-04-11 15:39 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-11 15:39 Jia-Ju Bai [this message]
2018-04-11 16:16 ` [PATCH v2] dec: tulip: de4x5: Replace mdelay with usleep_range in de4x5_hw_init James Bottomley
2018-04-12  1:30   ` Jia-Ju Bai
2018-04-12  2:21     ` arvindY
2018-04-12  2:26       ` Jia-Ju Bai

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