RE: [PATCH 2/4] media: platform: rzg2l-cru: rzg2l-ip: Add delay after D-PHY reset

[Biju Das <biju.das.jz@xxxxxxxxxxxxxx>]

Hi Laurent Pinchart,

Thanks for the feedback.

> -----Original Message-----
> From: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Sent: Tuesday, January 23, 2024 3:30 PM
> Subject: Re: [PATCH 2/4] media: platform: rzg2l-cru: rzg2l-ip: Add delay
> after D-PHY reset
> 
> Hi Biju,
> 
> Thank you for the patch.
> 
> On Tue, Jan 23, 2024 at 11:58:19AM +0000, Biju Das wrote:
> > As per section 35.3.1 Starting Reception for the MIPI CSI-2 Input on
> > the latest hardware manual(R01UH0914EJ0140 Rev.1.40) it is mentioned
> > that after DPHY reset, we need to wait for 1 msec or more before start
> > receiving data from the sensor. So add a delay after pre_streamon().
> >
> > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > ---
> >  drivers/media/platform/renesas/rzg2l-cru/rzg2l-ip.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-ip.c
> > b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-ip.c
> > index 9f351a05893e..5468dc179de7 100644
> > --- a/drivers/media/platform/renesas/rzg2l-cru/rzg2l-ip.c
> > +++ b/drivers/media/platform/renesas/rzg2l-cru/rzg2l-ip.c
> > @@ -5,6 +5,7 @@
> >   * Copyright (C) 2022 Renesas Electronics Corp.
> >   */
> >
> > +#include <linux/delay.h>
> >  #include "rzg2l-cru.h"
> >
> >  struct rzg2l_cru_ip_format {
> > @@ -71,6 +72,8 @@ static int rzg2l_cru_ip_s_stream(struct v4l2_subdev
> *sd, int enable)
> >  		if (ret)
> >  			return ret;
> >
> > +		usleep_range(1000, 2000);
> > +
> 
> What would you think of using
> 
> 		fsleep(1000);
> 
> instead ?

Essentially it is same by looking at the code[1].
OK will use fsleep()


[1]
static inline void fsleep(unsigned long usecs)
{
	if (usecs <= 10)
		udelay(usecs);
	else if (usecs <= 20000)
		usleep_range(usecs, 2 * usecs);
	else
		msleep(DIV_ROUND_UP(usecs, 1000));
}

Cheers,
Biju

> 
> With or without that,
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> 
> >  		ret = rzg2l_cru_start_image_processing(cru);
> >  		if (ret) {
> >  			v4l2_subdev_call(cru->ip.remote, video, post_streamoff);
> 
> --
> Regards,
> 
> Laurent Pinchart