[Freedreno] [PATCH] drm/msm: less magic numbers in msm_mdss_enable

[Dmitry Baryshkov]

On Wed, 1 Jun 2022 at 20:38, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
>
>
>
> On 6/1/2022 2:46 AM, Dmitry Baryshkov wrote:
> > On Wed, 1 Jun 2022 at 01:01, Abhinav Kumar <quic_abhinavk at quicinc.com> wrote:
> >> On 5/31/2022 5:18 AM, Dmitry Baryshkov wrote:
> >>> Replace magic register writes in msm_mdss_enable() with version that
> >>> contains less magic and more variable names that can be traced back to
> >>> the dpu_hw_catalog or the downstream dtsi files.
> >>>
> >>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov at linaro.org>
> >>> ---
> >>>    drivers/gpu/drm/msm/msm_mdss.c | 79 ++++++++++++++++++++++++++++++----
> >>>    1 file changed, 71 insertions(+), 8 deletions(-)
> >>>
> >>> diff --git a/drivers/gpu/drm/msm/msm_mdss.c b/drivers/gpu/drm/msm/msm_mdss.c
> >>> index 0454a571adf7..2a48263cd1b5 100644
> >>> --- a/drivers/gpu/drm/msm/msm_mdss.c
> >>> +++ b/drivers/gpu/drm/msm/msm_mdss.c
> >>> @@ -21,6 +21,7 @@
> >>>    #define HW_REV                              0x0
> >>>    #define HW_INTR_STATUS                      0x0010
> >>>
> >>> +#define UBWC_DEC_HW_VERSION          0x58
> >>>    #define UBWC_STATIC                 0x144
> >>>    #define UBWC_CTRL_2                 0x150
> >>>    #define UBWC_PREDICTION_MODE                0x154
> >>> @@ -132,9 +133,63 @@ static int _msm_mdss_irq_domain_add(struct msm_mdss *msm_mdss)
> >>>        return 0;
> >>>    }
> >>>
> >>> +#define UBWC_1_0 0x10000000
> >>> +#define UBWC_2_0 0x20000000
> >>> +#define UBWC_3_0 0x30000000
> >>> +#define UBWC_4_0 0x40000000
> >>> +
> >>> +static void msm_mdss_setup_ubwc_dec_20(struct msm_mdss *msm_mdss,
> >>> +                                    u32 ubwc_static)
> >>> +{
> >>> +     writel_relaxed(ubwc_static, msm_mdss->mmio + UBWC_STATIC);
> >>> +}
> >>> +
> >>> +static void msm_mdss_setup_ubwc_dec_30(struct msm_mdss *msm_mdss,
> >>> +                                    unsigned int ubwc_version,
> >>> +                                    u32 ubwc_swizzle,
> >>> +                                    u32 highest_bank_bit,
> >>> +                                    u32 macrotile_mode)
> >>> +{
> >>> +     u32 value = (ubwc_swizzle & 0x1) |
> >>> +                 (highest_bank_bit & 0x3) << 4 |
> >>> +                 (macrotile_mode & 0x1) << 12;
> >>> +
> >>> +     if (ubwc_version == UBWC_3_0)
> >>> +             value |= BIT(10);
> >>> +
> >>> +     if (ubwc_version == UBWC_1_0)
> >>> +             value |= BIT(8);
> >>> +
> >>> +     writel_relaxed(value, msm_mdss->mmio + UBWC_STATIC);
> >>> +}
> >>> +
> >>> +static void msm_mdss_setup_ubwc_dec_40(struct msm_mdss *msm_mdss,
> >>> +                                    unsigned int ubwc_version,
> >>> +                                    u32 ubwc_swizzle,
> >>> +                                    u32 ubwc_static,
> >>> +                                    u32 highest_bank_bit,
> >>> +                                    u32 macrotile_mode)
> >>> +{
> >>> +     u32 value = (ubwc_swizzle & 0x7) |
> >>> +                 (ubwc_static & 0x1) << 3 |
> >>> +                 (highest_bank_bit & 0x7) << 4 |
> >>> +                 (macrotile_mode & 0x1) << 12;
> >>> +
> >>> +     writel_relaxed(value, msm_mdss->mmio + UBWC_STATIC);
> >>> +
> >>> +     if (ubwc_version == UBWC_3_0) {
> >>> +             writel_relaxed(1, msm_mdss->mmio + UBWC_CTRL_2);
> >>> +             writel_relaxed(0, msm_mdss->mmio + UBWC_PREDICTION_MODE);
> >>> +     } else {
> >>> +             writel_relaxed(2, msm_mdss->mmio + UBWC_CTRL_2);
> >>> +             writel_relaxed(1, msm_mdss->mmio + UBWC_PREDICTION_MODE);
> >>> +     }
> >>> +}
> >>> +
> >>
> >> Is it possible to unify the above functions by having the internal
> >> ubwc_version checks?
> >
> > Note, it's not the ubwc_version, it is the ubwc_dec_hw_version. And
> > also different functions take different sets of arguments.
> >
> >> It seems like msm_mdss_setup_ubwc_dec_xxx can keep growing.
> >>
> >> I have not looked into each bit programming but from the top level so
> >> feel free to correct if wrong but it seems both do write UBWC_STATIC
> >> (different values based on different UBWC versions) and write some extra
> >> registers based on version
> >
> > This is what both the current code and the downstream do. See
> > https://github.com/MiCode/Xiaomi_Kernel_OpenSource/blob/zeus-s-oss/techpack/display-drivers/msm/sde/sde_hw_top.c#L312
> >
>
> Thanks for pointing to the downstream method for this,
>
> This is exactly what i was also suggesting to do when I mentioned
> unifying the above functions.
>
> So instead of having a separate function for each version why not handle
> all the versions in the same function like what the link you have shown
> does.

I wouldn't like that. The downstream uses hw_catalog to pass all
possible parameters. We do not, so we'd have a whole set of artificial
values.

>
> >>
> >>>    static int msm_mdss_enable(struct msm_mdss *msm_mdss)
> >>>    {
> >>>        int ret;
> >>> +     u32 hw_rev;
> >>>
> >>>        ret = clk_bulk_prepare_enable(msm_mdss->num_clocks, msm_mdss->clocks);
> >>>        if (ret) {
> >>> @@ -149,26 +204,34 @@ static int msm_mdss_enable(struct msm_mdss *msm_mdss)
> >>>        if (msm_mdss->is_mdp5)
> >>>                return 0;
> >>>
> >>> +     hw_rev = readl_relaxed(msm_mdss->mmio + HW_REV);
> >>> +     dev_info(msm_mdss->dev, "HW_REV: 0x%x\n", hw_rev);
> >>> +     dev_info(msm_mdss->dev, "UBWC_DEC_HW_VERSION: 0x%x\n",
> >>> +             readl_relaxed(msm_mdss->mmio + UBWC_DEC_HW_VERSION));
> >>
> >> we are already printing the HW version here
> >>
> >> https://gitlab.freedesktop.org/drm/msm/-/blob/msm-next/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c#L1096
> >>
> >> Do you want to remove that print then? May be. Let me take a look.
> >
> > [skipped]
> >



-- 
With best wishes
Dmitry