Re: [PATCH] drm/mediatek: dsi: Fix DSI host and panel bridge pre-enable order

["CK Hu (胡俊光)" <ck.hu@mediatek.com>]

On Tue, 2025-07-01 at 09:30 +0200, Louis-Alexis Eyraud wrote:
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> 
> Since commit c9b1150a68d9 ("drm/atomic-helper: Re-order bridge chain
> pre-enable and post-disable"), the bridge pre_enable callbacks are now
> called before crtc enable, and the bridge post_disable callbacks after
> the crtc disable.
> In the mediatek-drm driver, this change leads to transfer errors on
> mtk_dsi_host_transfer callback processing during the panel bridge
> pre-enable sequence because the DSI host bridge pre_enable and CRTC
> enable sequences, that are enabling the required clocks and PHY using
> mtk_dsi_poweron function, are called after.
> 
> So, in order to fix this call order issue, request the DSI host bridge
> be pre-enabled before panel bridge by setting pre_enable_prev_first
> flag on DSI device bridge in the mtk_dsi_host_attach function.

Reviewed-by: CK Hu <ck.hu@mediatek.com>

> 
> Fixes: c9b1150a68d9 ("drm/atomic-helper: Re-order bridge chain pre-enable and post-disable")
> Signed-off-by: Louis-Alexis Eyraud <louisalexis.eyraud@collabora.com>
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>