Re: [PATCH] staging: fbtft: replace udelay with usleep_range

From: Christos Kollintzas
Date: Sun Jul 10 2022 - 09:00:49 EST


On Sat, Jul 09, 2022 at 12:30:51PM +0200, Greg KH wrote:
> On Sat, Jul 09, 2022 at 01:06:56PM +0300, Christos Kollintzas wrote:
> > Adhere to Linux kernel coding style.
> >
> > Reported by checkpatch:
> >
> > CHECK: usleep_range is preferred over udelay
> >
> > Signed-off-by: Christos Kollintzas <c.kollintzas.92@xxxxxxxxx>
> > ---
> > drivers/staging/fbtft/fb_upd161704.c | 18 +++++++++---------
> > 1 file changed, 9 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/staging/fbtft/fb_upd161704.c b/drivers/staging/fbtft/fb_upd161704.c
> > index c680160d6380..eeafbab4ace1 100644
> > --- a/drivers/staging/fbtft/fb_upd161704.c
> > +++ b/drivers/staging/fbtft/fb_upd161704.c
> > @@ -32,27 +32,27 @@ static int init_display(struct fbtft_par *par)
> >
> > /* oscillator start */
> > write_reg(par, 0x003A, 0x0001); /*Oscillator 0: stop, 1: operation */
> > - udelay(100);
> > + usleep_range(100, 110);
>
> When doing these types of changes, you really need access to the
> hardware involved in order to be able to properly test it.
>
> Especially for this type of function which is trying to do timing
> changes which the hardware requires.
>
> Did you test this on the real hardware and did it work properly?
>
> thanks,
>
> greg k-h

I did not.

I will try to find the hardware and send a patch that is
properly tested.

thanks,

Christos Kollintzas