Re: [PATCH i-g-t v4 27/46] lib/unigraf: Allows sst/mst configuration

["Luca Ceresoli" <luca.ceresoli@bootlin.com>]

On Mon Nov 10, 2025 at 2:39 PM CET, Louis Chauvet wrote:
> Unigraf devices can emulate both SST and MST display port. In order to
> write tests using both, add fews helper to manipulate them.
>
> The define TSI_DPRX_NOT_DOCUMENTED_SIDEBAND_MSG_SUPPORT is taken from the
> python SDK, as it was not defined by the C sdk nor documented.
>
> Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>
> ---

[...]

> +bool unigraf_set_mst_stream_count(int count)
> +{
> +	int new_count;
> +
> +	igt_assert_lte(count, unigraf_get_mst_stream_max_count());
> +
> +	unigraf_write_u32(TSI_DPRX_MST_SINK_COUNT, count);
> +	new_count = unigraf_get_mst_stream_count();
> +
> +	igt_warn_on_f(count != new_count,
> +		      "IGT:%p: Requested MST stream count (%d) differ from what was applied by the device (%d)\n",
                                                               differs

> diff --git a/lib/unigraf/unigraf.h b/lib/unigraf/unigraf.h
> index 14e5fd984159..9fcae674b1d5 100644
> --- a/lib/unigraf/unigraf.h
> +++ b/lib/unigraf/unigraf.h
> @@ -93,4 +93,42 @@ void unigraf_plug(void);
>   */
>  void unigraf_unplug(void);
>
> +/**
> + * unigraf_set_sst() - Configure the device for Single Stream Transport mode
> + *
> + * This function sets the device to operate in Single Stream Transport (SST) mode.
> + */
> +void unigraf_set_sst(void);
> +
> +/**
> + * unigraf_set_mst() - Configure the device for Multi Stream Transport mode
> + *
> + * This function sets the device to operate in Multi Stream Transport (MST) mode.
> + */
> +void unigraf_set_mst(void);
> +
> +/**
> + * unigraf_get_mst_stream_count() - Get the current number of MST streams
> + *
> + * Returns: The current number of MST streams configured on the device.
> + */
> +int unigraf_get_mst_stream_count(void);
> +
> +/**
> + * unigraf_set_mst_stream_count() - Set the number of accepted stream count
> + *
> + * Returns true when the stream count was properly applied, false if the final stream count
> + * is not the one requested
> + */
> +bool unigraf_set_mst_stream_count(int count);
> +
> +/**
> + * unigraf_get_mst_stream_max_count() - Get the maximum number of stream count accepted by the
> + * device
> + * Caution: This function can be destructive to some configuration: the only way to get the
> + * information is to try and read the new value.
> + */
> +int unigraf_get_mst_stream_max_count(void);
> +void unigraf_select_stream(int stream);

This function is not documented.

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com