linux-kernel - Re: [PATCH v3,3/3] drm/mediatek: dp: Add the audio divider to mtk_dp

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Message-ID: <16d2f0d7-f150-823b-b568-18f3bb6b2f77@baylibre.com>
Date:   Thu, 20 Jul 2023 14:29:47 +0200
From:   Alexandre Mergnat <amergnat@...libre.com>
To:     AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>,
        Shuijing Li <shuijing.li@...iatek.com>,
        chunkuang.hu@...nel.org, p.zabel@...gutronix.de, airlied@...il.com,
        daniel@...ll.ch, robh+dt@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, conor+dt@...nel.org,
        matthias.bgg@...il.com, jitao.shi@...iatek.com
Cc:     dri-devel@...ts.freedesktop.org,
        linux-mediatek@...ts.infradead.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        Project_Global_Chrome_Upstream_Group@...iatek.com
Subject: Re: [PATCH v3,3/3] drm/mediatek: dp: Add the audio divider to
 mtk_dp_data struct



On 20/07/2023 14:08, AngeloGioacchino Del Regno wrote:
> Il 20/07/23 14:07, Alexandre Mergnat ha scritto:
>>
>>
>> On 20/07/2023 13:54, AngeloGioacchino Del Regno wrote:
>>> Il 20/07/23 12:14, Alexandre Mergnat ha scritto:
>>>>
>>>>
>>>> On 20/07/2023 10:26, Shuijing Li wrote:
>>>>> Due to the difference of HW, different dividers need to be set.
>>>>>
>>>>> Signed-off-by: Shuijing Li <shuijing.li@...iatek.com>
>>>>> Signed-off-by: Jitao Shi <jitao.shi@...iatek.com>
>>>>> ---
>>>>> Changes in v3:
>>>>> Separate these two things into two different patches.
>>>>> per suggestion from the previous thread:
>>>>> https://lore.kernel.org/lkml/e2ad22bcba31797f38a12a488d4246a01bf0cb2e.camel@mediatek.com/
>>>>> Changes in v2:
>>>>> - change the variables' name to be more descriptive
>>>>> - add a comment that describes the function of 
>>>>> mtk_dp_audio_sample_arrange
>>>>> - reduce indentation by doing the inverse check
>>>>> - add a definition of some bits
>>>>> - add support for mediatek, mt8188-edp-tx
>>>>> per suggestion from the previous thread:
>>>>> https://lore.kernel.org/lkml/ac0fcec9-a2fe-06cc-c727-189ef7babe9c@collabora.com/
>>>>> ---
>>>>>   drivers/gpu/drm/mediatek/mtk_dp.c     | 7 ++++++-
>>>>>   drivers/gpu/drm/mediatek/mtk_dp_reg.h | 1 +
>>>>>   2 files changed, 7 insertions(+), 1 deletion(-)
>>>>>
>> ...
>>>>> b/drivers/gpu/drm/mediatek/mtk_dp_reg.h
>>>>> index f38d6ff12afe..6d7f0405867e 100644
>>>>> --- a/drivers/gpu/drm/mediatek/mtk_dp_reg.h
>>>>> +++ b/drivers/gpu/drm/mediatek/mtk_dp_reg.h
>>>>> @@ -162,6 +162,7 @@
>>>>>   #define AUDIO_M_CODE_MULT_DIV_SEL_DP_ENC0_P0_MUL_2    (1 << 8)
>>>>>   #define AUDIO_M_CODE_MULT_DIV_SEL_DP_ENC0_P0_MUL_4    (2 << 8)
>>>>>   #define AUDIO_M_CODE_MULT_DIV_SEL_DP_ENC0_P0_MUL_8    (3 << 8)
>>>>> +#define MT8188_AUDIO_M_CODE_MULT_DIV_SEL_DP_ENC0_P0_DIV_2    (4 << 8)
>>>>
>>>> IMO, it's a bit weird to have SoC specific define in the generic 
>>>> header.
>>>> Are you sure this bit is only available for MT8188 ?
>>>>
>>>
>>> Eh, the P0_DIV2 bit is 5<<8 for MT8195, while for 8188 it's 4<<8, 
>>> clearly :-)
>>>
>>
>> Ok then, to avoid this kind of issue for other SoCs in the future, is 
>> that make sense for you to do a SoC specific header file beside the 
>> generic one?
>>
> 
> For just one definition? That's a bit overkill :-)
> 

You're right, but we must start somewhere ^^, and show the proper way 
for future patches. Actually, I gave my Reviewed-by because it's only 
one definition. This will be fixed later (I hope).

>>>>>   #define AUDIO_M_CODE_MULT_DIV_SEL_DP_ENC0_P0_DIV_2    (5 << 8)
>>>>>   #define AUDIO_M_CODE_MULT_DIV_SEL_DP_ENC0_P0_DIV_4    (6 << 8)
>>>>>   #define AUDIO_M_CODE_MULT_DIV_SEL_DP_ENC0_P0_DIV_8    (7 << 8)
>>>>
>>>> Reviewed-by: Alexandre Mergnat <amergnat@...libre.com>
>>>>
>>>
>>>
>>
> 
> 

-- 
Regards,
Alexandre