On Tue, Mar 10, 2026 at 01:47:47PM +0100, Konrad Dybcio wrote:
> On 3/6/26 5:47 PM, Dmitry Baryshkov wrote:
> > The UBWC registers in the MDSS region are not dependent on the UBWC
> > version (it is an invalid assumption we inherited from the vendor SDE
> > driver). Instead they are dependent only on the MDSS core revision.
> >
> > Rework UBWC programming to follow MDSS revision and to use required (aka
> > encoder) UBWC version instead of the ubwc_dec_version.
> >
> > Fixes: d68db6069a8e ("drm/msm/mdss: convert UBWC setup to use match data")
> > Signed-off-by: Dmitry Baryshkov <[email protected]>
> > ---
> > drivers/gpu/drm/msm/msm_mdss.c | 120
> > ++++++++++++++++-------------------------
> > 1 file changed, 45 insertions(+), 75 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/msm_mdss.c b/drivers/gpu/drm/msm/msm_mdss.c
> > index 9047e8d9ee89..9f81f43283b9 100644
> > --- a/drivers/gpu/drm/msm/msm_mdss.c
> > +++ b/drivers/gpu/drm/msm/msm_mdss.c
> > @@ -166,27 +166,27 @@ static int _msm_mdss_irq_domain_add(struct msm_mdss
> > *msm_mdss)
> > return 0;
> > }
> >
> > -static void msm_mdss_setup_ubwc_dec_20(struct msm_mdss *msm_mdss)
> > +static void msm_mdss_setup_ubwc_v4(struct msm_mdss *msm_mdss)
> > {
> > const struct qcom_ubwc_cfg_data *data = msm_mdss->mdss_data;
> > - u32 value = MDSS_UBWC_STATIC_UBWC_SWIZZLE(data->ubwc_swizzle) |
> > + u32 value = MDSS_UBWC_STATIC_UBWC_SWIZZLE(data->ubwc_swizzle & 0x1) |
>
> The field takes bit0/1/2 for *enabling* level 1/2/3 swizzling - is this
> intended?
Not on MDSS v4. I need to rename the functions for better understanding.
>
> [...]
>
> > +static void msm_mdss_setup_ubwc_v5(struct msm_mdss *msm_mdss)
> > {
> > const struct qcom_ubwc_cfg_data *data = msm_mdss->mdss_data;
> > - u32 value = MDSS_UBWC_STATIC_UBWC_SWIZZLE(data->ubwc_swizzle & 0x1) |
> > + u32 value = MDSS_UBWC_STATIC_UBWC_SWIZZLE(data->ubwc_swizzle) |
> > MDSS_UBWC_STATIC_HIGHEST_BANK_BIT(data->highest_bank_bit -
> > 13);
> >
> > + if (data->ubwc_bank_spread)
> > + value |= MDSS_UBWC_STATIC_UBWC_BANK_SPREAD;
>
>
> 8250 is ubwcv4 (in our catalog anyway) and definitely has a bit for this
8250 has MDSS 6.0
>
> Konrad
--
With best wishes
Dmitry
