Commit 683853b1 authored by Imre Deak's avatar Imre Deak
Browse files

drm/i915/dp: Ack only the handled device service IRQs 



Only those IRQs should be acked that are handled, however for SST all
IRQs triggered by the sink are acked. This can be a problem for flags
that are reserved/reading zero at a given moment, but become used for
some purpose - with a side-effect if set - in a future DPCD revision.

Fix the above by acking only those device service IRQs that will be
handled. While at it add asserts that only the known/acked device
service IRQs are handled both in the MST and SST case.

Reviewed-by: default avatarLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260225164618.1261368-20-imre.deak@intel.com
parent 0f3675d6

drivers/gpu/drm/i915/display/intel_dp.c

+14 −0
Original line number Diff line number Diff line
@@ -4929,6 +4929,14 @@ intel_dp_mst_disconnect(struct intel_dp *intel_dp) 
	drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst.mgr, intel_dp->is_mst);

}



#define INTEL_DP_DEVICE_SERVICE_IRQ_MASK_SST	(DP_AUTOMATED_TEST_REQUEST | \

						 DP_CP_IRQ | \

						 DP_SINK_SPECIFIC_IRQ)



#define INTEL_DP_DEVICE_SERVICE_IRQ_MASK_MST	(DP_CP_IRQ | \

						 DP_DOWN_REP_MSG_RDY | \

						 DP_UP_REQ_MSG_RDY)



static bool

intel_dp_get_sink_irq_esi(struct intel_dp *intel_dp, u8 *esi)

{
@@ -5026,6 +5034,8 @@ static bool intel_dp_get_and_ack_sink_irq_esi_sst(struct intel_dp *intel_dp, u8 
		    encoder->base.base.id, encoder->base.name,

		    esi);



	esi[1] &= INTEL_DP_DEVICE_SERVICE_IRQ_MASK_SST;



	if (mem_is_zero(&esi[1], 3))

		return true;
@@ -5570,6 +5580,8 @@ intel_dp_check_mst_status(struct intel_dp *intel_dp) 
		if (mem_is_zero(ack, sizeof(ack)))

			break;



		drm_WARN_ON(display->drm, ack[1] & ~INTEL_DP_DEVICE_SERVICE_IRQ_MASK_MST);



		if (!intel_dp_ack_sink_irq_esi(intel_dp, ack))

			drm_dbg_kms(display->drm, "Failed to ack ESI\n");
@@ -5854,6 +5866,8 @@ static void intel_dp_handle_device_service_irq(struct intel_dp *intel_dp, u8 irq 
{

	struct intel_display *display = to_intel_display(intel_dp);



	drm_WARN_ON(display->drm, irq_mask & ~INTEL_DP_DEVICE_SERVICE_IRQ_MASK_SST);



	if (irq_mask & DP_AUTOMATED_TEST_REQUEST)

		intel_dp_test_request(intel_dp);