diff mbox series

staging: fbtft: replace udelay with usleep_range

Message ID YslTQLhM7GSaGXki@mandalorian.koija (mailing list archive)
State Not Applicable
Headers show
Series staging: fbtft: replace udelay with usleep_range | expand

Commit Message

Christos Kollintzas July 9, 2022, 10:06 a.m. UTC
Adhere to Linux kernel coding style.

Reported by checkpatch:

CHECK: usleep_range is preferred over udelay

Signed-off-by: Christos Kollintzas <c.kollintzas.92@gmail.com>
---
 drivers/staging/fbtft/fb_upd161704.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

Comments

Greg Kroah-Hartman July 9, 2022, 10:30 a.m. UTC | #1
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@gmail.com>
> ---
>  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
Christos Kollintzas July 10, 2022, 1 p.m. UTC | #2
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@gmail.com>
> > ---
> >  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
diff mbox series

Patch

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);
 
 	/* y-setting */
 	write_reg(par, 0x0024, 0x007B);	/* amplitude setting */
-	udelay(10);
+	usleep_range(10, 15);
 	write_reg(par, 0x0025, 0x003B);	/* amplitude setting */
 	write_reg(par, 0x0026, 0x0034);	/* amplitude setting */
-	udelay(10);
+	usleep_range(10, 15);
 	write_reg(par, 0x0027, 0x0004);	/* amplitude setting */
 	write_reg(par, 0x0052, 0x0025);	/* circuit setting 1 */
-	udelay(10);
+	usleep_range(10, 15);
 	write_reg(par, 0x0053, 0x0033);	/* circuit setting 2 */
 	write_reg(par, 0x0061, 0x001C);	/* adjustment V10 positive polarity */
-	udelay(10);
+	usleep_range(10, 15);
 	write_reg(par, 0x0062, 0x002C);	/* adjustment V9 negative polarity */
 	write_reg(par, 0x0063, 0x0022);	/* adjustment V34 positive polarity */
-	udelay(10);
+	usleep_range(10, 15);
 	write_reg(par, 0x0064, 0x0027);	/* adjustment V31 negative polarity */
-	udelay(10);
+	usleep_range(10, 15);
 	write_reg(par, 0x0065, 0x0014);	/* adjustment V61 negative polarity */
-	udelay(10);
+	usleep_range(10, 15);
 	write_reg(par, 0x0066, 0x0010);	/* adjustment V61 negative polarity */
 
 	/* Basical clock for 1 line (BASECOUNT[7:0]) number specified */
@@ -60,7 +60,7 @@  static int init_display(struct fbtft_par *par)
 
 	/* Power supply setting */
 	write_reg(par, 0x0019, 0x0000);	/* DC/DC output setting */
-	udelay(200);
+	usleep_range(200, 210);
 	write_reg(par, 0x001A, 0x1000);	/* DC/DC frequency setting */
 	write_reg(par, 0x001B, 0x0023);	/* DC/DC rising setting */
 	write_reg(par, 0x001C, 0x0C01);	/* Regulator voltage setting */