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Commit 0bf25146 authored by Tomi Valkeinen's avatar Tomi Valkeinen Committed by Andrzej Hajda
Browse files

drm/bridge: tc358767: cleanup LT result check 



The driver has a loop after ending link training, where it reads the
DPCD link status and prints an error if that status is not ok.

The loop is unnecessary, as far as I can understand from DP specs, so
let's remove it. We can also print the more specific errors to help
debugging.

Signed-off-by: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: default avatarAndrzej Hajda <a.hajda@samsung.com>
Signed-off-by: default avatarAndrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528082747.3631-16-tomi.valkeinen@ti.com
parent 0776a269

drivers/gpu/drm/bridge/tc358767.c

+35 −27
Original line number Diff line number Diff line
@@ -980,34 +980,42 @@ static int tc_main_link_enable(struct tc_data *tc) 
	if (ret < 0)

		goto err_dpcd_write;



	/* Wait */

	timeout = 100;

	do {

		udelay(1);

		/* Read DPCD 0x202-0x207 */

		ret = drm_dp_dpcd_read_link_status(aux, tmp + 2);

	/* Check link status */

	ret = drm_dp_dpcd_read_link_status(aux, tmp);

	if (ret < 0)

		goto err_dpcd_read;

	} while ((--timeout) &&

		 !(drm_dp_channel_eq_ok(tmp + 2,  tc->link.base.num_lanes)));



	if (timeout == 0) {

		/* Read DPCD 0x200-0x201 */

		ret = drm_dp_dpcd_read(aux, DP_SINK_COUNT, tmp, 2);

		if (ret < 0)

			goto err_dpcd_read;

		dev_err(dev, "channel(s) EQ not ok\n");

		dev_info(dev, "0x0200 SINK_COUNT: 0x%02x\n", tmp[0]);

		dev_info(dev, "0x0201 DEVICE_SERVICE_IRQ_VECTOR: 0x%02x\n",

			 tmp[1]);

		dev_info(dev, "0x0202 LANE0_1_STATUS: 0x%02x\n", tmp[2]);

		dev_info(dev, "0x0204 LANE_ALIGN_STATUS_UPDATED: 0x%02x\n",

			 tmp[4]);

		dev_info(dev, "0x0205 SINK_STATUS: 0x%02x\n", tmp[5]);

		dev_info(dev, "0x0206 ADJUST_REQUEST_LANE0_1: 0x%02x\n",

			 tmp[6]);



		return -EAGAIN;

	ret = 0;



	value = tmp[0] & DP_CHANNEL_EQ_BITS;



	if (value != DP_CHANNEL_EQ_BITS) {

		dev_err(tc->dev, "Lane 0 failed: %x\n", value);

		ret = -ENODEV;

	}



	if (tc->link.base.num_lanes == 2) {

		value = (tmp[0] >> 4) & DP_CHANNEL_EQ_BITS;



		if (value != DP_CHANNEL_EQ_BITS) {

			dev_err(tc->dev, "Lane 1 failed: %x\n", value);

			ret = -ENODEV;

		}



		if (!(tmp[2] & DP_INTERLANE_ALIGN_DONE)) {

			dev_err(tc->dev, "Interlane align failed\n");

			ret = -ENODEV;

		}

	}



	if (ret) {

		dev_err(dev, "0x0202 LANE0_1_STATUS:            0x%02x\n", tmp[0]);

		dev_err(dev, "0x0203 LANE2_3_STATUS             0x%02x\n", tmp[1]);

		dev_err(dev, "0x0204 LANE_ALIGN_STATUS_UPDATED: 0x%02x\n", tmp[2]);

		dev_err(dev, "0x0205 SINK_STATUS:               0x%02x\n", tmp[3]);

		dev_err(dev, "0x0206 ADJUST_REQUEST_LANE0_1:    0x%02x\n", tmp[4]);

		dev_err(dev, "0x0207 ADJUST_REQUEST_LANE2_3:    0x%02x\n", tmp[5]);

		goto err;

	}



	return 0;