Messages in this thread | | | Date | Wed, 3 May 2023 10:10:11 -0700 | Subject | Re: [PATCH 1/4] drm/msm/dsi: Adjust pclk rate for compression | From | Jessica Zhang <> |
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On 5/3/2023 1:33 AM, Dmitry Baryshkov wrote: > On 03/05/2023 04:19, Jessica Zhang wrote: >> Divide the pclk rate by the compression ratio when DSC is enabled >> >> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com> >> --- >> drivers/gpu/drm/msm/dsi/dsi_host.c | 14 ++++++++++---- >> 1 file changed, 10 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c >> b/drivers/gpu/drm/msm/dsi/dsi_host.c >> index 43a5ec33eee8..35c69dbe5f6f 100644 >> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c >> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c >> @@ -561,7 +561,8 @@ 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_get_pclk_rate(const struct drm_display_mode >> *mode, >> + struct drm_dsc_config *dsc, bool is_bonded_dsi) >> { >> unsigned long pclk_rate; >> @@ -576,6 +577,11 @@ 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 pclk by compression ratio */ >> + if (dsc) >> + pclk_rate = DIV_ROUND_UP(pclk_rate, >> + dsc->bits_per_component * 3 / msm_dsc_get_bpp_int(dsc)); >> + > > Don't we loose precision here? > Would DIV_ROUND_UP(pclk_rate * bpp, dsc->bpc * 3) be better?
Hi Dmitry,
Acked.
Thanks,
Jessica Zhang
> >> return pclk_rate; >> } >> @@ -585,7 +591,7 @@ 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 +610,7 @@ 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 +640,7 @@ 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; >> > > -- > With best wishes > Dmitry >
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