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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>
This commit is contained in:
Jia-Ju Bai 2018-01-25 18:32:59 +08:00 committed by Tejun Heo
parent e72685dbd2
commit eada8598e6
1 changed files with 1 additions and 1 deletions
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2
drivers/ata/pata_it821x.c
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@ -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);
}
kfree(buf);
printk(KERN_ERR "it821x_firmware_command: timeout\n");