[PATCH] drm/amd/dc: Read from DP_SINK_COUNT_ESI for DPDC r1.2 or higher

[Aurabindo Pillai]

On Tue, 2020-08-04 at 11:42 +0800, Wayne Lin wrote:
> [Why]
> According to DP spec, DPRX with DPCD r1.2 or higher shall have the
> same Link/Sink Device Status field registers at DPCD Addresses 00200h
> through 00205h to the corresponding DPRX Event Status Indicator
> registers at DPCD Addresses 02002h through 0200Fh. We now only read
> from
> 02002h when DPCD revision number is r1.4 or higher while handling
> short
> HPD. Need to correct that.
> 
> [How]
> Set to read from 02002h when DPCD is r1.2 or higher
> 
> Signed-off-by: Wayne Lin <
> Wayne.Lin at amd.com
> >
> ---
>  drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> index 2bfa4e35c2cf..9fb1543b4c73 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
> @@ -1834,9 +1834,9 @@ static enum dc_status read_hpd_rx_irq_data(
>  	 * fail, so we now explicitly read 6 bytes which is
>  	 * the req from the above mentioned test cases.
>  	 *
> -	 * For DP 1.4 we need to read those from 2002h range.
> +	 * For DPCD r1.2 or higher, we need to read those from 2002h
> range.
>  	 */
> -	if (link->dpcd_caps.dpcd_rev.raw < DPCD_REV_14)
> +	if (link->dpcd_caps.dpcd_rev.raw < DPCD_REV_12)
>  		retval = core_link_read_dpcd(
>  			link,
>  			DP_SINK_COUNT,

Reviewed-by: Aurabindo Pillai <aurabindo.pillai at amd.com>