linux-kernel - Re: [PATCH 3/5] drm/panel: mantix: Improve power off sequence

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Message-ID: <d0751b98-86d6-4088-a4c4-cfa77fe0c241@linaro.org>
Date: Tue, 6 Jan 2026 09:15:19 +0100
From: Neil Armstrong <neil.armstrong@...aro.org>
To: sebastian.krzyszkowiak@...i.sm, Guido Günther
 <agx@...xcpu.org>, Purism Kernel Team <kernel@...i.sm>,
 Jessica Zhang <jesszhan0024@...il.com>,
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>,
 David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>
Cc: dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 3/5] drm/panel: mantix: Improve power off sequence

On 1/5/26 21:24, Sebastian Krzyszkowiak via B4 Relay wrote:
> From: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@...i.sm>
> 
> According to the sequence from section 7.3.4 of FT8006P datasheet,
> TP_RSTN and RESX should be asserted after disabling AVDD and AVEE and
> together with VDDI.
> 
> Also, AVEE power down needs to happen at least 150ms after entering
> sleep mode.
> 
> Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@...i.sm>
> ---
>   drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c | 12 ++++++++----
>   1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c b/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c
> index bb5489e4d7a9..0e66ee7a727d 100644
> --- a/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c
> +++ b/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c
> @@ -96,6 +96,9 @@ static int mantix_disable(struct drm_panel *panel)
>   	mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
>   	mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);
>   
> +	/* T10 */
> +	mipi_dsi_msleep(&dsi_ctx, 150);
> +
>   	return dsi_ctx.accum_err;
>   }
>   
> @@ -103,15 +106,16 @@ static int mantix_unprepare(struct drm_panel *panel)
>   {
>   	struct mantix *ctx = panel_to_mantix(panel);
>   
> -	gpiod_set_value_cansleep(ctx->tp_rstn_gpio, 1);
> -	usleep_range(5000, 6000);
> -	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> -
>   	regulator_disable(ctx->avee);
>   	regulator_disable(ctx->avdd);
>   	/* T11 */
>   	usleep_range(5000, 6000);
>   	regulator_disable(ctx->vddi);
> +
> +	gpiod_set_value_cansleep(ctx->tp_rstn_gpio, 1);
> +	usleep_range(5000, 6000);
> +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +
>   	/* T14 */
>   	msleep(50);
>   
> 

Reviewed-by: Neil Armstrong <neil.armstrong@...aro.org>

Thanks,
Neil