Hi Laurent Pinchart,
> -----Original Message-----
> From: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Sent: Tuesday, January 23, 2024 6:46 PM
> Subject: Re: [PATCH 2/4] media: platform: rzg2l-cru: rzg2l-ip: Add delay
> after D-PHY reset
>
> On Tue, Jan 23, 2024 at 06:38:00PM +0000, Biju Das wrote:
> > 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()
>
> Yes, it will result in the same delay. fsleep() is recommended as the
> default sleep function unless there's a specific need to do something
> different.
OK. Thanks for the explanation.
Cheers,
Biju
>
> > [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));
> > }
> >
> > > 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
