[Intel-gfx] [PATCH 09/13] drm/edid: add drm_edid_read_switcheroo()

[Nautiyal, Ankit K]

LGTM.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>

On 4/21/2023 5:17 PM, Jani Nikula wrote:
> Add a switcheroo variant to the struct drm_edid based EDID read
> functions.
>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>   drivers/gpu/drm/drm_edid.c | 29 +++++++++++++++++++++++++++++
>   include/drm/drm_edid.h     |  2 ++
>   2 files changed, 31 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 813ce00a106a..941f3d53a701 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -2844,6 +2844,35 @@ struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
>   }
>   EXPORT_SYMBOL(drm_get_edid_switcheroo);
>   
> +/**
> + * drm_edid_read_switcheroo - get EDID data for a vga_switcheroo output
> + * @connector: connector we're probing
> + * @adapter: I2C adapter to use for DDC
> + *
> + * Wrapper around drm_edid_read_ddc() for laptops with dual GPUs using one set
> + * of outputs. The wrapper adds the requisite vga_switcheroo calls to
> + * temporarily switch DDC to the GPU which is retrieving EDID.
> + *
> + * Return: Pointer to valid EDID or %NULL if we couldn't find any.
> + */
> +const struct drm_edid *drm_edid_read_switcheroo(struct drm_connector *connector,
> +						struct i2c_adapter *adapter)
> +{
> +	struct drm_device *dev = connector->dev;
> +	struct pci_dev *pdev = to_pci_dev(dev->dev);
> +	const struct drm_edid *drm_edid;
> +
> +	if (drm_WARN_ON_ONCE(dev, !dev_is_pci(dev->dev)))
> +		return NULL;
> +
> +	vga_switcheroo_lock_ddc(pdev);
> +	drm_edid = drm_edid_read_ddc(connector, adapter);
> +	vga_switcheroo_unlock_ddc(pdev);
> +
> +	return drm_edid;
> +}
> +EXPORT_SYMBOL(drm_edid_read_switcheroo);
> +
>   /**
>    * drm_edid_duplicate - duplicate an EDID and the extensions
>    * @edid: EDID to duplicate
> diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
> index 571885d32907..169755d3de19 100644
> --- a/include/drm/drm_edid.h
> +++ b/include/drm/drm_edid.h
> @@ -613,6 +613,8 @@ const struct drm_edid *drm_edid_read_ddc(struct drm_connector *connector,
>   const struct drm_edid *drm_edid_read_custom(struct drm_connector *connector,
>   					    int (*read_block)(void *context, u8 *buf, unsigned int block, size_t len),
>   					    void *context);
> +const struct drm_edid *drm_edid_read_switcheroo(struct drm_connector *connector,
> +						struct i2c_adapter *adapter);
>   int drm_edid_connector_update(struct drm_connector *connector,
>   			      const struct drm_edid *edid);
>   int drm_edid_connector_add_modes(struct drm_connector *connector);