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authorJia-Ju Bai <baijiaju1990@gmail.com>2018-03-18 22:49:57 +0800
committerDominik Brodowski <linux@dominikbrodowski.net>2018-10-01 12:15:21 +0200
commitbe826ada52f1fcabed5b5217c94609ebf5967211 (patch)
treedf45b2847e07a1ad49e5cce85802bf504eafe3de /drivers/char
parentdc245cfa82f4dc1e9adf6b9190a9d7dfb1554ecf (diff)
char: pcmcia: cm4000_cs: Replace mdelay with usleep_range in set_protocol
set_protocol() is never called in atomic context. The call chains ending up at set_protocol() are: [1] set_protocol() <- monitor_card() [2] set_protocol() <- cmm_ioctl() monitor_card() is only set in setup_timer(), and cmm_ioctl() is only set as ".unlocked_ioctl" in file_operations structure "cm4000_fops". Despite never getting called from atomic context, set_protocol() calls mdelay(10), i.e. busy wait for 10ms. That 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. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Acked-by: Harald Welte <laforge@gnumonks.org> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/pcmcia/cm4000_cs.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/char/pcmcia/cm4000_cs.c b/drivers/char/pcmcia/cm4000_cs.c
index a219964cb770..809507bf8f1c 100644
--- a/drivers/char/pcmcia/cm4000_cs.c
+++ b/drivers/char/pcmcia/cm4000_cs.c
@@ -530,7 +530,7 @@ static int set_protocol(struct cm4000_dev *dev, struct ptsreq *ptsreq)
DEBUGP(5, dev, "NumRecBytes is valid\n");
break;
}
- mdelay(10);
+ usleep_range(10000, 11000);
}
if (i == 100) {
DEBUGP(5, dev, "Timeout waiting for NumRecBytes getting "
@@ -546,7 +546,7 @@ static int set_protocol(struct cm4000_dev *dev, struct ptsreq *ptsreq)
DEBUGP(2, dev, "NumRecBytes = %i\n", num_bytes_read);
break;
}
- mdelay(10);
+ usleep_range(10000, 11000);
}
/* check whether it is a short PTS reply? */