@@ -2244,6 +2244,8 @@ static const struct dpcd_quirk dpcd_quirk_list[] = {
{ OUI(0x90, 0xCC, 0x24), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) },
/* Apple MacBookPro 2017 15 inch eDP Retina panel reports too low DP_MAX_LINK_RATE */
{ OUI(0x00, 0x10, 0xfa), DEVICE_ID(101, 68, 21, 101, 98, 97), false, BIT(DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS) },
+ /* DELL P2715Q MST payload table must be reset after the two last payload slots get allocated. */
+ { OUI(0x00, 0xe0, 0x4c), DEVICE_ID('D', 'p', '1', '.', '2', 0), true, BIT(DP_DPCD_QUIRK_MST_PAYLOAD_TABLE_RESET_WA) },
};
#undef OUI
@@ -620,6 +620,14 @@ enum drm_dp_quirk {
* the DP_MAX_LINK_RATE register reporting a lower max multiplier.
*/
DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS,
+ /**
+ * @DP_DPCD_QUIRK_MST_PAYLOAD_TABLE_RESET_WA:
+ *
+ * An bug in the MST branch device's payload allocation logic requires
+ * the payload table to be reset after its last two payload slots get
+ * allocated.
+ */
+ DP_DPCD_QUIRK_MST_PAYLOAD_TABLE_RESET_WA,
};
/**
The DELL P2715Q monitor's MST hub has a payload allocation problem, where the VCPI used to reserve the last two time slots (at position 0x3e, 0x3f) in the hub's payload table, this VCPI can't be reused for later payload configurations. To work around the problem in a follow-up patch the driver needs to reset the payload table after all payloads have been freed; add a quirk the driver can use to detect the monitor and apply the WA if needed. Cc: Lyude Paul <lyude@redhat.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: dri-devel@lists.freedesktop.org Signed-off-by: Imre Deak <imre.deak@intel.com> --- drivers/gpu/drm/display/drm_dp_helper.c | 2 ++ include/drm/display/drm_dp_helper.h | 8 ++++++++ 2 files changed, 10 insertions(+)