[PATCH] ata: pata_pdc2027x: Replace mdelay with msleep

[PATCH] ata: pata_pdc2027x: Replace mdelay with msleep

[Jia-Ju Bai]

After checking all possible call chains to pdc_adjust_pll and
pdc_detect_pll_input_clock,
my tool finds that these functions are never called in atomic context,
namely never in an interrupt handler or holding a spinlock.
And their caller functions pdc2027x_init_one and pdc2027x_reinit_one 
calls pci_enable_device which can sleep, and no spinlock is held when
calling pdc_adjust_pll and pdc_detect_pll_input_clock,
so it proves that pdc_adjust_pll and pdc_detect_pll_input_clock 
can call functions which can sleep.
Thus mdelay can be replaced with msleep to avoid busy wait.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
 drivers/ata/pata_pdc2027x.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/ata/pata_pdc2027x.c b/drivers/ata/pata_pdc2027x.c
index ffd8d33..4e8584d 100644
--- a/drivers/ata/pata_pdc2027x.c
+++ b/drivers/ata/pata_pdc2027x.c
@@ -580,7 +580,7 @@ static void pdc_adjust_pll(struct ata_host *host, long pll_clock, unsigned int b
 	ioread16(mmio_base + PDC_PLL_CTL); /* flush */
 
 	/* Wait the PLL circuit to be stable */
-	mdelay(30);
+	msleep(30);
 
 #ifdef PDC_DEBUG
 	/*
@@ -620,7 +620,7 @@ static long pdc_detect_pll_input_clock(struct ata_host *host)
 	start_time = ktime_get();
 
 	/* Let the counter run for 100 ms. */
-	mdelay(100);
+	msleep(100);
 
 	/* Read the counter values again */
 	end_count = pdc_read_counter(host);
-- 
1.7.9.5

Re: [PATCH] ata: pata_pdc2027x: Replace mdelay with msleep

[Tejun Heo]

On Thu, Jan 25, 2018 at 06:45:05PM +0800, Jia-Ju Bai wrote:
> After checking all possible call chains to pdc_adjust_pll and
> pdc_detect_pll_input_clock,
> my tool finds that these functions are never called in atomic context,
> namely never in an interrupt handler or holding a spinlock.
> And their caller functions pdc2027x_init_one and pdc2027x_reinit_one 
> calls pci_enable_device which can sleep, and no spinlock is held when
> calling pdc_adjust_pll and pdc_detect_pll_input_clock,
> so it proves that pdc_adjust_pll and pdc_detect_pll_input_clock 
> can call functions which can sleep.
> Thus mdelay can be replaced with msleep to avoid busy wait.
> 
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>

Applied to libata/for-4.16.

Thanks.

-- 
tejun