Re: [PATCH] staging: fbtft: Replace mdelay() with msleep() and usleep_range()

From: Jia-Ju Bai
Date: Fri Jul 27 2018 - 07:43:38 EST




On 2018/7/27 18:34, Andy Shevchenko wrote:
On Fri, Jul 27, 2018 at 12:21 PM, Jia-Ju Bai <baijiaju1990@xxxxxxxxx> wrote:
reset() and init_display() are never called in atomic context.
They call mdelay() to busily wait, which is not necessary.
mdelay() can be replaced with msleep().
gpio_set_value(par->gpio.reset, 0);
udelay(20);
gpio_set_value(par->gpio.reset, 1);
- mdelay(120);
+ msleep(120);
I didn't look to the rest, but this one will be inconsistent after your patch.

The question here is why udelay() is needed, while mdelay() changed?


I thought udelay() is used for short delay, so it is not very necessary to change udelay() to usleep_range().
mdelay() is used for longer delay, so I changed it to msleep().

If you think udelay() should be also changed, I can send a new patch :)


Best wishes,
Jia-Ju Bai