* [PATCH 2/2] net: can: sja1000: Replace mdelay with usleep_range in pcan_add_channels
@ 2018-04-11 1:43 Jia-Ju Bai
0 siblings, 0 replies; only message in thread
From: Jia-Ju Bai @ 2018-04-11 1:43 UTC (permalink / raw)
To: wg, mkl; +Cc: linux-can, netdev, linux-kernel, Jia-Ju Bai
pcan_add_channels() is never called in atomic context.
pcan_add_channels() is only called by pcan_probe(), which is only set as
".probe" in struct pcmcia_driver.
Despite never getting called from atomic context, pcan_add_channels()
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>
---
drivers/net/can/sja1000/peak_pcmcia.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/can/sja1000/peak_pcmcia.c b/drivers/net/can/sja1000/peak_pcmcia.c
index dd56133..1a1fbf3 100644
--- a/drivers/net/can/sja1000/peak_pcmcia.c
+++ b/drivers/net/can/sja1000/peak_pcmcia.c
@@ -530,7 +530,7 @@ static int pcan_add_channels(struct pcan_pccard *card)
pcan_write_reg(card, PCC_CCR, ccr);
/* wait 2ms before unresetting channels */
- mdelay(2);
+ usleep_range(2000, 3000);
ccr &= ~PCC_CCR_RST_ALL;
pcan_write_reg(card, PCC_CCR, ccr);
--
1.9.1
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