Re: [PATCH] drm/panel: ilitek-ili9881c: do not fail probe if iovcc is absent

[neil . armstrong]

On 7/13/26 10:22, David Oberhollenzer wrote:
> Commit 4c95b2b7d49e ("drm/panel: ilitek-ili9881c: support Waveshare
> 7.0" DSI panel") adds an additional iovcc regulator that other
> Ilitek ili9881c based panels apparently do not have or need.
>
> The commit goes out of its way to make usage of this new regulator
> optional, dutifully testing if the field in `struct ili9881c` is NULL
> before touching the new regulator. However, in the probe function,
> it unconditionally fails if devm_regulator_get_optional returns an
> error.
>
> devm_regulator_get_optional() returns -ENODEV if the regulator is
> missing, causing probe to fail for other panels that do not have
> an iovcc-supply set in the device tree.
>
> Fixes: 4c95b2b7d49e ("drm/panel: ilitek-ili9881c: support Waveshare 7.0" DSI panel")
> Signed-off-by: David Oberhollenzer <david.oberhollenzer@xxxxxxxxxxxxx>
> ---
>   drivers/gpu/drm/panel/panel-ilitek-ili9881c.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c b/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c
> index 0652cdb57d11..6c8d02712566 100644
> --- a/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c
> +++ b/drivers/gpu/drm/panel/panel-ilitek-ili9881c.c
> @@ -2562,9 +2562,12 @@ static int ili9881c_dsi_probe(struct mipi_dsi_device *dsi)
>   				     "Couldn't get our power regulator\n");
>   
>   	ctx->iovcc = devm_regulator_get_optional(&dsi->dev, "iovcc");
> -	if (IS_ERR(ctx->iovcc))
> -		return dev_err_probe(&dsi->dev, PTR_ERR(ctx->iovcc),
> +	if (IS_ERR(ctx->iovcc)) {
> +		if (PTR_ERR(ctx->iovcc) != -ENODEV)
> +			return dev_err_probe(&dsi->dev, PTR_ERR(ctx->iovcc),
>   				     "Couldn't get our iovcc regulator\n");
> +		ctx->iovcc = NULL;
> +	}
>   
>   	ctx->reset = devm_gpiod_get_optional(&dsi->dev, "reset", GPIOD_OUT_LOW);
>   	if (IS_ERR(ctx->reset))

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

Thanks,
Neil