Re: [PATCH v6 07/13] drm/imx: dc: Use TCON operation mode

[Maxime Ripard]

Hi,

On Fri, Sep 04, 2026 at 03:54:57PM +0800, Liu Ying wrote:
> @@ -273,7 +285,22 @@ dc_crtc_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_commit *state)
>  	dc_ed_pec_sync_trigger(dc_crtc->ed_cont);
>  	dc_ed_pec_sync_trigger(dc_crtc->ed_safe);
>  	dc_fg_shdtokgen(dc_crtc->fg);
> +
> +	/* Don't relinquish CPU until TCON is set to operation mode. */
> +	local_irq_save(flags);
> +	preempt_disable();
> +
>  	dc_fg_enable(dc_crtc->fg);
> +	/*
> +	 * Turn TCON into operation mode as soon as the first dumb
> +	 * frame is generated by DC(we don't relinquish CPU to ensure
> +	 * this).  This makes DPR/PRG be able to evade the frame.
> +	 */
> +	DC_CRTC_WAIT_FOR_FRAMEGEN_FRAME_INDEX_MOVING(dc_crtc->fg);
> +	dc_tc_set_operation_mode(dc_crtc->tc);
> +
> +	local_irq_restore(flags);
> +	preempt_enable();

That's really not great... Can you expand on why you need this, and is
there really no other way to do it?

Maxime

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