[PATCH] drm/radeon: don't probe MST on hw we don't support it on

[Christian König]

On 18.06.2015 06:29, Dave Airlie wrote:
> From: Dave Airlie <airlied at redhat.com>
>
> If you do radeon.mst=1 on a gpu without mst hw, and then
> plug some mst hw it will oops instead of falling back.
>
> So check we have DCE5 at least before proceeding.
>
> Signed-off-by: Dave Airlie <airlied at redhat.com>

Reviewed-by: Christian König <christian.koenig at amd.com>

BTW: Since Alex is on vacation I'm managing drm-fixes for Radeon/Amdgpu 
for a while.

Should I add that patch to my pull request on Friday or do you wan to 
add it directly?

Regards,
Christian.

> ---
>   drivers/gpu/drm/radeon/radeon_dp_mst.c | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_dp_mst.c b/drivers/gpu/drm/radeon/radeon_dp_mst.c
> index 2b98ed3..257b10be 100644
> --- a/drivers/gpu/drm/radeon/radeon_dp_mst.c
> +++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c
> @@ -663,12 +663,17 @@ int
>   radeon_dp_mst_probe(struct radeon_connector *radeon_connector)
>   {
>   	struct radeon_connector_atom_dig *dig_connector = radeon_connector->con_priv;
> +	struct drm_device *dev = radeon_connector->base.dev;
> +	struct radeon_device *rdev = dev->dev_private;
>   	int ret;
>   	u8 msg[1];
>   
>   	if (!radeon_mst)
>   		return 0;
>   
> +	if (!ASIC_IS_DCE5(rdev))
> +		return 0;
> +
>   	if (dig_connector->dpcd[DP_DPCD_REV] < 0x12)
>   		return 0;
>