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| author | Jia-Ju Bai <baijiaju1990@gmail.com> | 2018-03-18 15:49:57 +0100 |
|---|---|---|
| committer | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-10-01 12:15:21 +0200 |
| commit | be826ada52f1fcabed5b5217c94609ebf5967211 (patch) | |
| tree | df45b2847e07a1ad49e5cce85802bf504eafe3de /drivers/char/pcmcia | |
| parent | pcmcia: Use module_pcmcia_driver for scsi drivers (diff) | |
| download | linux-be826ada52f1fcabed5b5217c94609ebf5967211.tar.xz linux-be826ada52f1fcabed5b5217c94609ebf5967211.zip | |
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/pcmcia')
| -rw-r--r-- | drivers/char/pcmcia/cm4000_cs.c | 4 |
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? */ |