Re: [PATCH v3 8/9] drm/panel: novatek-nt36672a: Add panel for Asus Zenfone Max Pro M1

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] drm/panel: skipped deinit delays on DSI command failure
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commit 3072360323238f49eea2657047c2842ee3b0aa0f
Author: Alexey Minnekhanov <alexeymin@minlexx.ru>

drm/panel: novatek-nt36672a: Add panel for Asus Zenfone Max Pro M1

This commit adds support for the TXD TXDI600YANPA-43V3 video mode panel based
on Novatek NT36672A, used in the Asus Zenfone Max Pro M1 smartphone.

> diff --git a/drivers/gpu/drm/panel/panel-novatek-nt36672a.c b/drivers/gpu/drm/panel/panel-novatek-nt36672a.c
> index 48dff2279b0e9..7d7c79d2502d2 100644
> --- a/drivers/gpu/drm/panel/panel-novatek-nt36672a.c
> +++ b/drivers/gpu/drm/panel/panel-novatek-nt36672a.c
[ ... ]
> +static void txd_x00td_deinit_cmds(struct mipi_dsi_multi_context *dsi_ctx)
> +{
> +	mipi_dsi_dcs_set_display_off_multi(dsi_ctx);
> +	mipi_dsi_msleep(dsi_ctx, 50);
> +	mipi_dsi_dcs_enter_sleep_mode_multi(dsi_ctx);
> +	mipi_dsi_msleep(dsi_ctx, 120);

[Severity: Medium]
If a preceding DSI command fails, dsi_ctx->accum_err will be set, which causes
mipi_dsi_msleep() to completely skip its delay:

#define mipi_dsi_msleep(ctx, delay) \
	do { \
		if (!(ctx)->accum_err) \
			msleep(delay); \
	} while (0)

Could this result in the regulators being prematurely powered off while the
panel is still active or transitioning? 

Safe power-down sequences typically require hardware delays regardless of
whether the sleep commands successfully transmitted. Should this code either
reset dsi_ctx->accum_err prior to sleeping, or use an unconditional msleep()
instead to guarantee the hardware settles?

> +}
> +
>  static const struct drm_display_mode tianma_fhd_video_panel_default_mode = {
>  	.clock		= 161331,
>

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Sashiko AI review · https://sashiko.dev/#/patchset/20261011-nt36672a-panels-v3-0-9ea238627f8a@minlexx.ru?part=8