Message-ID: <451b114c-05e1-541c-1d3e-26bb81a307c4@linaro.org>
Date:   Sun, 4 Jun 2023 05:21:07 +0300
From:   Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To:     Abhinav Kumar <quic_abhinavk@...cinc.com>
Cc:     freedreno@...ts.freedesktop.org, linux-arm-msm@...r.kernel.org,
        linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        quic_khsieh@...cinc.com, Rob Clark <robdclark@...il.com>,
        Daniel Vetter <daniel@...ll.ch>, quic_jesszhan@...cinc.com,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        David Airlie <airlied@...il.com>, Sean Paul <sean@...rly.run>
Subject: Re: [Freedreno] [PATCH] drm/msm/dpu: re-introduce dpu core revision
 to the catalog

On 31/05/2023 21:25, Abhinav Kumar wrote:
> 
> 
> On 5/31/2023 3:07 AM, Dmitry Baryshkov wrote:
>> On 31/05/2023 06:05, Abhinav Kumar wrote:
>>>
>>>
>>> On 5/30/2023 7:53 PM, Dmitry Baryshkov wrote:
>>>> On Wed, 31 May 2023 at 03:54, Abhinav Kumar 
>>>> <quic_abhinavk@...cinc.com> wrote:
>>>>>
>>>>> With [1] dpu core revision was dropped in favor of using the
>>>>> compatible string from the device tree to select the dpu catalog
>>>>> being used in the device.
>>>>>
>>>>> This approach works well however also necessitates adding catalog
>>>>> entries for small register level details as dpu capabilities and/or
>>>>> features bloating the catalog unnecessarily. Examples include but
>>>>> are not limited to data_compress, interrupt register set, widebus etc.
>>>>>
>>>>> Introduce the dpu core revision back as an entry to the catalog so 
>>>>> that
>>>>> we can just use dpu revision checks and enable those bits which
>>>>> should be enabled unconditionally and not controlled by a catalog
>>>>> and also simplify the changes to do something like:
>>>>>
>>>>> if (dpu_core_revision > xxxxx && dpu_core_revision < xxxxx)
>>>>>          enable the bit;
>>>>>
>>>>> Also, add some of the useful macros back to be able to use dpu core
>>>>> revision effectively.
>>>>>
>>>>> [1]: 
>>>>> https://patchwork.freedesktop.org/patch/530891/?series=113910&rev=4
>>>>>
>>>>> Signed-off-by: Abhinav Kumar <quic_abhinavk@...cinc.com>
>>>>> ---
>>>>>   .../msm/disp/dpu1/catalog/dpu_3_0_msm8998.h   |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_4_0_sdm845.h    |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_5_0_sm8150.h    |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_5_1_sc8180x.h   |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_6_0_sm8250.h    |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_6_2_sc7180.h    |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_6_3_sm6115.h    |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_6_5_qcm2290.h   |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_7_0_sm8350.h    |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_7_2_sc7280.h    |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_8_0_sc8280xp.h  |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_8_1_sm8450.h    |  1 +
>>>>>   .../msm/disp/dpu1/catalog/dpu_9_0_sm8550.h    |  1 +
>>>>>   .../gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h    | 31 
>>>>> ++++++++++++++++++-
>>>>>   14 files changed, 43 insertions(+), 1 deletion(-)
>>>>>
>>>>
>>>> [skipped catalog changes]
>>>>
>>>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h 
>>>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
>>>>> index 677048cc3b7d..cc4aa75a1219 100644
>>>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
>>>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
>>>>> @@ -19,6 +19,33 @@
>>>>>    */
>>>>>   #define MAX_BLOCKS    12
>>>>>
>>>>> +#define DPU_HW_VER(MAJOR, MINOR, STEP)\
>>>>> +                 ((((unsigned int)MAJOR & 0xF) << 28) |\
>>>>> +                 ((MINOR & 0xFFF) << 16) |\
>>>>> +                 (STEP & 0xFFFF))
>>>>> +
>>>>> +#define DPU_HW_MAJOR(rev)((rev) >> 28)
>>>>> +#define DPU_HW_MINOR(rev)(((rev) >> 16) & 0xFFF)
>>>>> +#define DPU_HW_STEP(rev)((rev) & 0xFFFF)
>>>>> +#define DPU_HW_MAJOR_MINOR(rev)((rev) >> 16)
>>>>> +
>>>>> +#define IS_DPU_MAJOR_MINOR_SAME(rev1, rev2)   \
>>>>> +(DPU_HW_MAJOR_MINOR((rev1)) == DPU_HW_MAJOR_MINOR((rev2)))
>>>>> +
>>>>> +#define DPU_HW_VER_300 DPU_HW_VER(3, 0, 0) /* 8998 v1.0 */
>>>>> +#define DPU_HW_VER_400 DPU_HW_VER(4, 0, 0) /* sdm845 v1.0 */
>>>>> +#define DPU_HW_VER_500 DPU_HW_VER(5, 0, 0) /* sm8150 v1.0 */
>>>>> +#define DPU_HW_VER_510 DPU_HW_VER(5, 1, 1) /* sc8180 */
>>>>> +#define DPU_HW_VER_600 DPU_HW_VER(6, 0, 0) /* sm8250 */
>>>>> +#define DPU_HW_VER_620 DPU_HW_VER(6, 2, 0) /* sc7180 v1.0 */
>>>>> +#define DPU_HW_VER_630 DPU_HW_VER(6, 3, 0) /* sm6115|sm4250 */
>>>>> +#define DPU_HW_VER_650 DPU_HW_VER(6, 5, 0) /* qcm2290|sm4125 */
>>>>> +#define DPU_HW_VER_700 DPU_HW_VER(7, 0, 0) /* sm8350 */
>>>>> +#define DPU_HW_VER_720 DPU_HW_VER(7, 2, 0) /* sc7280 */
>>>>> +#define DPU_HW_VER_800 DPU_HW_VER(8, 0, 0) /* sc8280xp */
>>>>> +#define DPU_HW_VER_810 DPU_HW_VER(8, 1, 0) /* sm8450 */
>>>>> +#define DPU_HW_VER_900 DPU_HW_VER(9, 0, 0) /* sm8550 */
>>>>
>>>> Instead of having defines for all SoCs (which can quickly become
>>>> unmanageable) and can cause merge conflicts, I'd suggest inlining all
>>>> the defines into respective catalog files.
>>>>
>>>
>>> Sure, that can be done.
>>>
>>>> Also, I'm not sure that the "step" should be a part of the catalog. I
>>>> know that this follows the hardware revision. However, please correct
>>>> me if I'm wrong, different step levels are used for revisions of the
>>>> same SoC. The original code that was reading the hw revision from the
>>>> hardware register, listed both 5.0.0 and 5.0.1 for sm8150.
>>>>
>>>
>>> This is one of the things i noticed while making this change.
>>>
>>> Before the catalog rework, we used to handle even steps as we used to 
>>> read that from the register and match it with the mdss_cfg handler. 
>>> But after the rework, we dont handle steps anymore. Yes, you are 
>>> right that different step levels are used for the revisions of the 
>>> same SOC and so with that, i dont expect or atleast am not aware of 
>>> DPU differences between steps but I am not able to rule it out.
>>>
>>> So are you suggesting we drop step altogether and DPU_HW_VER() macro 
>>> shall only handle major and minor versions? With the current chipsets 
>>> I see, it should not make a difference . Its just that I am not sure 
>>> if that will never happen.
>>
>> Yes. The goal of this rework would be to drop generic features and to 
>> replace those checks with DPU-revision lookups. Correct?
> 
> Yes thats right.
> 
>> I think that from this perspective having to handle toe step revision 
>> is a sign of an overkill. Having to handle the step revision is a sign 
>> of paltform feature (or mis-feature) rather than a generic DPU bit.
>>
> 
> Not entirely. Lets not forget that at the moment even dpu_perf_cfg is 
> part of the catalog. Even if in terms of major HW blocks steps shouldnt 
> change, there is absolutely no guarantee that perf data cannot.
> 
> This is what is the sticking point for me which is holding me back 
> against dropping step. Thoughts?

We usually do not support ES versions of the chips, only the final 
version. So supporting the perf data for earlier revisions is also not 
required.

> 
>> In fact I suppose that even handling a minor revision would be an 
>> overkill. Why don't we start with .dpu_major instead of .core_rev? We 
>> can add .dpu_minor if/when required.
>>
> 
> No, unfortunately we cannot drop minor version for sure. I am seeing 
> examples in downstream code where some of the features are available 
> after a minor verion as well.

Can you please give an example?

> 
>>>
>>>>> +
>>>>>   #define DPU_HW_BLK_NAME_LEN    16
>>>>>
>>>>>   #define MAX_IMG_WIDTH 0x3fff
>>>>> @@ -769,7 +796,7 @@ struct dpu_perf_cfg {
>>>>>   /**
>>>>>    * struct dpu_mdss_cfg - information of MDSS HW
>>>>>    * This is the main catalog data structure representing
>>>>> - * this HW version. Contains number of instances,
>>>>> + * this HW version. Contains dpu core revision, number of instances,
>>>>>    * register offsets, capabilities of the all MDSS HW sub-blocks.
>>>>>    *
>>>>>    * @dma_formats        Supported formats for dma pipe
>>>>> @@ -778,6 +805,8 @@ struct dpu_perf_cfg {
>>>>>    * @mdss_irqs:         Bitmap with the irqs supported by the target
>>>>>    */
>>>>>   struct dpu_mdss_cfg {
>>>>> +       u32 core_rev;
>>>>> +
>>>>>          const struct dpu_caps *caps;
>>>>>
>>>>>          const struct dpu_ubwc_cfg *ubwc;
>>>>> -- 
>>>>> 2.40.1
>>>>>
>>>>
>>>>
>>

-- 
With best wishes
Dmitry

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