Re: [PATCH 07/18] media: rcar-csi2: Fix typo

[Tomi Valkeinen]

Hi,

On 19/02/2025 16:46, Niklas Söderlund wrote:
> On 2025-02-19 16:36:27 +0200, Tomi Valkeinen wrote:
> > Hi,
> >
> > On 19/02/2025 16:24, Niklas Söderlund wrote:
> > > Hi Tomi,
> > >
> > > On 2025-02-19 15:49:01 +0200, Tomi Valkeinen wrote:
> > > > Fix typo with variable name 'msps'.
> > >
> > > FWIW, this is not a typo, C-PHY uses symbols per seconds, not bits per
> > > second.
> >
> > Hmm, but the code calls rcsi2_calc_mbps() and uses the returned value as
> > msps. How can that be right, if it's symbols?
>
> I don't recall all the details off hand, but IIRC it's just a naming
> thing in the specification. I'm fine with using either, just wanted to
> point out it was not a typo but intentional name.

Ok. I don't mind either way that much, it was just very confusing. I'm 
not familiar with C-PHY, but I thought usually "symbol" is something 
else than a single bit. As msps is used in some other places in the 
file, adding a comment to the place where we switch from mbps to msps 
should be enough.

 Tomi

> >   Tomi
> >
> > > > Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
> > > > ---
> > > >    drivers/media/platform/renesas/rcar-csi2.c | 10 +++++-----
> > > >    1 file changed, 5 insertions(+), 5 deletions(-)
> > > >
> > > > diff --git a/drivers/media/platform/renesas/rcar-csi2.c b/drivers/media/platform/renesas/rcar-csi2.c
> > > > index 845fb3e155f1..92697ea3df01 100644
> > > > --- a/drivers/media/platform/renesas/rcar-csi2.c
> > > > +++ b/drivers/media/platform/renesas/rcar-csi2.c
> > > > @@ -1301,7 +1301,7 @@ static int rcsi2_start_receiver_v4h(struct rcar_csi2 *priv,
> > > >    	const struct rcar_csi2_format *format;
> > > >    	const struct v4l2_mbus_framefmt *fmt;
> > > >    	unsigned int lanes;
> > > > -	int msps;
> > > > +	int mbps;
> > > >    	int ret;
> > > >    	/* Use the format on the sink pad to compute the receiver config. */
> > > > @@ -1314,9 +1314,9 @@ static int rcsi2_start_receiver_v4h(struct rcar_csi2 *priv,
> > > >    	if (ret)
> > > >    		return ret;
> > > > -	msps = rcsi2_calc_mbps(priv, format->bpp, lanes);
> > > > -	if (msps < 0)
> > > > -		return msps;
> > > > +	mbps = rcsi2_calc_mbps(priv, format->bpp, lanes);
> > > > +	if (mbps < 0)
> > > > +		return mbps;
> > > >    	/* Reset LINK and PHY*/
> > > >    	rcsi2_write(priv, V4H_CSI2_RESETN_REG, 0);
> > > > @@ -1352,7 +1352,7 @@ static int rcsi2_start_receiver_v4h(struct rcar_csi2 *priv,
> > > >    	rcsi2_write16(priv, V4H_PPI_RW_COMMON_CFG_REG, 0x0003);
> > > >    	/* C-PHY settings */
> > > > -	ret = rcsi2_c_phy_setting_v4h(priv, msps);
> > > > +	ret = rcsi2_c_phy_setting_v4h(priv, mbps);
> > > >    	if (ret)
> > > >    		return ret;
> > > >
> > > > --
> > > > 2.43.0