Re: [PATCH] ASoC: mediatek: mt8188: Enable apll1 clock during reg rw to prevent hang

["Trevor Wu (吳文良)" <Trevor.Wu@mediatek.com>]

On Tue, 2024-12-03 at 17:07 -0300, Nícolas F. R. A. Prado wrote:

> 
> Currently, booting the Genio 700 EVK board with the MT8188 sound
> platform driver configured as a module (CONFIG_SND_SOC_MT8188=m)
> results
> in a system hang right when the HW registers for the audio controller
> are read:
> 
>   mt8188-audio 10b10000.audio-controller: No cache defaults, reading
> back from HW
> 
> The hang doesn't occur with the driver configured as builtin as then
> the
> unused clocks are still enabled.
> 
> Enable the apll1 clock during register read/write to prevent the
> hang.
> 
> Signed-off-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
> ---
>  sound/soc/mediatek/mt8188/mt8188-afe-clk.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/sound/soc/mediatek/mt8188/mt8188-afe-clk.c
> b/sound/soc/mediatek/mt8188/mt8188-afe-clk.c
> index
> e69c1bb2cb239596dee50b166c20192d5408be10..fb8cf286df3f02ac076528b898f
> d0d7a708ec1ea 100644
> --- a/sound/soc/mediatek/mt8188/mt8188-afe-clk.c
> +++ b/sound/soc/mediatek/mt8188/mt8188-afe-clk.c
> @@ -587,6 +587,8 @@ int mt8188_afe_enable_reg_rw_clk(struct
> mtk_base_afe *afe)
>         mt8188_afe_enable_clk(afe, afe_priv-
> >clk[MT8188_CLK_AUD_A1SYS_HP]);
>         mt8188_afe_enable_clk(afe, afe_priv-
> >clk[MT8188_CLK_AUD_A1SYS]);
> 
> +       mt8188_afe_enable_clk(afe, afe_priv-
> >clk[MT8188_CLK_APMIXED_APLL1]);
> +
>         return 0;
>  }
Hi Nicolas,

If I understand correctly, APLL1 should be the parent clock of
AUD_A1SYS_HP and AUD_A1SYS, so it should be enabled automatically by
CCF.

I'm not sure why you resolved the hang issue after enabling APLL1.
Could you share more details about the solution?

Thanks,
Trevor

> 
> @@ -594,6 +596,8 @@ int mt8188_afe_disable_reg_rw_clk(struct
> mtk_base_afe *afe)
>  {
>         struct mt8188_afe_private *afe_priv = afe->platform_priv;
> 
> +       mt8188_afe_disable_clk(afe, afe_priv-
> >clk[MT8188_CLK_APMIXED_APLL1]);
> +
>         mt8188_afe_disable_clk(afe, afe_priv-
> >clk[MT8188_CLK_AUD_A1SYS]);
>         mt8188_afe_disable_clk(afe, afe_priv-
> >clk[MT8188_CLK_AUD_A1SYS_HP]);
>         mt8188_afe_disable_clk(afe, afe_priv-
> >clk[MT8188_CLK_AUD_AFE]);
> 
> ---
> base-commit: b852e1e7a0389ed6168ef1d38eb0bad71a6b11e8
> change-id: 20241203-mt8188-afe-fix-hang-disabled-apll1-clk-
> b3c11782cbaf
> 
> Best regards,
> --
> Nícolas F. R. A. Prado <nfraprado@collabora.com>
> 
>