path: root/drivers
diff options
authorJia-Ju Bai <baijiaju1990@gmail.com>2018-01-25 18:32:59 +0800
committerTejun Heo <tj@kernel.org>2018-01-25 07:28:23 -0800
commiteada8598e69f9ff767c387951f40bab5aafe6a88 (patch)
tree8646a9f0e57abd09f8287337ff9359209f86284b /drivers
parente72685dbd2e7782ce99ccd198e52dc0d9cf1d16f (diff)
ata: pata_it821x: Replace mdelay with usleep_range in it821x_firmware_command
After checking all possible call chains to it821x_firmware_command here, my tool finds that it821x_firmware_command is never called in atomic context, namely never in an interrupt handler or holding a spinlock. And it821x_firmware_command calls kmalloc(GFP_KERNEL), so it proves again that it821x_firmware_command can call functions which can sleep. Thus mdelay can be replaced with usleep_range to avoid busy wait. This is found by a static analysis tool named DCNS written by myself. Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'drivers')
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/ata/pata_it821x.c b/drivers/ata/pata_it821x.c
index 7a21edf89e72..8468b300193b 100644
--- a/drivers/ata/pata_it821x.c
+++ b/drivers/ata/pata_it821x.c
@@ -683,7 +683,7 @@ static u8 *it821x_firmware_command(struct ata_port *ap, u8 cmd, int len)
ioread16_rep(ap->ioaddr.data_addr, buf, len/2);
return (u8 *)buf;
- mdelay(1);
+ usleep_range(500, 1000);
printk(KERN_ERR "it821x_firmware_command: timeout\n");

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