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Commit df0c237d authored by Jesse Barnes's avatar Jesse Barnes Committed by Keith Packard
Browse files

drm/i915/dp: consolidate AUX retry code 



When checking link status during a hot plug event or detecting sink
presence, we need to retry 3 times per the spec (section 9.1 of the 1.1a
DisplayPort spec).  Consolidate the retry code into a
native_aux_read_retry function for use by get_link_status and _detect.

Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: default avatarKeith Packard <keithp@keithp.com>
Signed-off-by: default avatarKeith Packard <keithp@keithp.com>
parent 885a5014

drivers/gpu/drm/i915/intel_dp.c

+30 −21
Original line number Diff line number Diff line
@@ -1012,21 +1012,23 @@ intel_dp_dpms(struct drm_encoder *encoder, int mode) 
}



/*

 * Fetch AUX CH registers 0x202 - 0x207 which contain

 * link status information

 * Native read with retry for link status and receiver capability reads for

 * cases where the sink may still be asleep.

 */

static bool

intel_dp_get_link_status(struct intel_dp *intel_dp)

intel_dp_aux_native_read_retry(struct intel_dp *intel_dp, uint16_t address,

			       uint8_t *recv, int recv_bytes)

{

	int ret, i;



	/* Must try AUX reads for this at least 3 times */

	/*

	 * Sinks are *supposed* to come up within 1ms from an off state,

	 * but we're also supposed to retry 3 times per the spec.

	 */

	for (i = 0; i < 3; i++) {

		ret = intel_dp_aux_native_read(intel_dp,

					       DP_LANE0_1_STATUS,

					       intel_dp->link_status,

					       DP_LINK_STATUS_SIZE);

		if (ret == DP_LINK_STATUS_SIZE)

		ret = intel_dp_aux_native_read(intel_dp, address, recv,

					       recv_bytes);

		if (ret == recv_bytes)

			return true;

		msleep(1);

	}
@@ -1034,6 +1036,19 @@ intel_dp_get_link_status(struct intel_dp *intel_dp) 
	return false;

}



/*

 * Fetch AUX CH registers 0x202 - 0x207 which contain

 * link status information

 */

static bool

intel_dp_get_link_status(struct intel_dp *intel_dp)

{

	return intel_dp_aux_native_read_retry(intel_dp,

					      DP_LANE0_1_STATUS,

					      intel_dp->link_status,

					      DP_LINK_STATUS_SIZE);

}



static uint8_t

intel_dp_link_status(uint8_t link_status[DP_LINK_STATUS_SIZE],

		     int r)
@@ -1549,7 +1564,7 @@ static enum drm_connector_status 
ironlake_dp_detect(struct intel_dp *intel_dp)

{

	enum drm_connector_status status;

	int ret, i;

	bool ret;



	/* Can't disconnect eDP, but you can close the lid... */

	if (is_edp(intel_dp)) {
@@ -1560,17 +1575,11 @@ ironlake_dp_detect(struct intel_dp *intel_dp) 
	}



	status = connector_status_disconnected;

	for (i = 0; i < 3; i++) {

		ret = intel_dp_aux_native_read(intel_dp,

	ret = intel_dp_aux_native_read_retry(intel_dp,

					     0x000, intel_dp->dpcd,

					     sizeof (intel_dp->dpcd));

		if (ret == sizeof(intel_dp->dpcd) &&

		    intel_dp->dpcd[DP_DPCD_REV] != 0) {

	if (ret && intel_dp->dpcd[DP_DPCD_REV] != 0)

		status = connector_status_connected;

			break;

		}

		msleep(1);

	}

	DRM_DEBUG_KMS("DPCD: %hx%hx%hx%hx\n", intel_dp->dpcd[0],

		      intel_dp->dpcd[1], intel_dp->dpcd[2], intel_dp->dpcd[3]);

	return status;