Re: [PATCH v4 2/5] drm/msm/dsi: Adjust pclk rate for compression

[Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>]

On 5/22/2023 2:31 PM, Marijn Suijten wrote:
> On 2023-05-22 13:30:21, Jessica Zhang wrote:
> > Adjust the pclk rate to divide hdisplay by the compression ratio when DSC
> > is enabled.
> >
> > Signed-off-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
>
> As discussed previously, this patch would apply a lot more cleanly on
> top of:
>
> https://lore.kernel.org/linux-arm-msm/20230520200103.4019607-1-dmitry.baryshkov@xxxxxxxxxx/T/#u
>
> (This is the v2 that doesn't change the callback, but does change the
> code flow so that you have to *touch less lines* in this patch).

Hi Marijn,

Sounds good. I'll rebase on top of that.

Thanks,

Jessica Zhang

> - Marijn
>
> > ---
> >   drivers/gpu/drm/msm/dsi/dsi_host.c | 23 +++++++++++++++++++----
> >   1 file changed, 19 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > index 18d38b90eb28..d04f8bbd707d 100644
> > --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> > +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> > @@ -561,7 +561,18 @@ void dsi_link_clk_disable_v2(struct msm_dsi_host *msm_host)
> >   	clk_disable_unprepare(msm_host->byte_clk);
> >   }
> >   
> > -static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode, bool is_bonded_dsi)
> > +static unsigned long dsi_adjust_compressed_pclk(const struct drm_display_mode *mode,
> > +		const struct drm_dsc_config *dsc)
> > +{
> > +	int new_hdisplay = DIV_ROUND_UP(mode->hdisplay * drm_dsc_get_bpp_int(dsc),
> > +			dsc->bits_per_component * 3);
> > +
> > +	return (new_hdisplay + (mode->htotal - mode->hdisplay))
> > +			* mode->vtotal * drm_mode_vrefresh(mode);
> > +}
> > +
> > +static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode,
> > +		const struct drm_dsc_config *dsc, bool is_bonded_dsi)
> >   {
> >   	unsigned long pclk_rate;
> >   
> > @@ -576,6 +587,10 @@ static unsigned long dsi_get_pclk_rate(const struct drm_display_mode *mode, bool
> >   	if (is_bonded_dsi)
> >   		pclk_rate /= 2;
> >   
> > +	/* If DSC is enabled, divide hdisplay by compression ratio */
> > +	if (dsc)
> > +		pclk_rate = dsi_adjust_compressed_pclk(mode, dsc);
> > +
> >   	return pclk_rate;
> >   }
> >   
> > @@ -585,7 +600,7 @@ unsigned long dsi_byte_clk_get_rate(struct mipi_dsi_host *host, bool is_bonded_d
> >   	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
> >   	u8 lanes = msm_host->lanes;
> >   	u32 bpp = dsi_get_bpp(msm_host->format);
> > -	unsigned long pclk_rate = dsi_get_pclk_rate(mode, is_bonded_dsi);
> > +	unsigned long pclk_rate = dsi_get_pclk_rate(mode, msm_host->dsc, is_bonded_dsi);
> >   	u64 pclk_bpp = (u64)pclk_rate * bpp;
> >   
> >   	if (lanes == 0) {
> > @@ -604,7 +619,7 @@ unsigned long dsi_byte_clk_get_rate(struct mipi_dsi_host *host, bool is_bonded_d
> >   
> >   static void dsi_calc_pclk(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
> >   {
> > -	msm_host->pixel_clk_rate = dsi_get_pclk_rate(msm_host->mode, is_bonded_dsi);
> > +	msm_host->pixel_clk_rate = dsi_get_pclk_rate(msm_host->mode, msm_host->dsc, is_bonded_dsi);
> >   	msm_host->byte_clk_rate = dsi_byte_clk_get_rate(&msm_host->base, is_bonded_dsi,
> >   							msm_host->mode);
> >   
> > @@ -634,7 +649,7 @@ int dsi_calc_clk_rate_v2(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
> >   
> >   	dsi_calc_pclk(msm_host, is_bonded_dsi);
> >   
> > -	pclk_bpp = (u64)dsi_get_pclk_rate(msm_host->mode, is_bonded_dsi) * bpp;
> > +	pclk_bpp = (u64)dsi_get_pclk_rate(msm_host->mode, msm_host->dsc, is_bonded_dsi) * bpp;
> >   	do_div(pclk_bpp, 8);
> >   	msm_host->src_clk_rate = pclk_bpp;
> >   
> >
> > --
> > 2.40.1