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drm/bridge: tc358767: cleanup LT result check

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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: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190528082747.3631-16-tomi.valkeinen@ti.com
This commit is contained in:
Tomi Valkeinen 2019-05-28 11:27:38 +03:00 committed by Andrzej Hajda
parent 0776a269d7
commit 0bf2514651
1 changed files with 34 additions and 26 deletions
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60
drivers/gpu/drm/bridge/tc358767.c
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@ -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);
if (ret < 0)
goto err_dpcd_read;
} while ((--timeout) &&
!(drm_dp_channel_eq_ok(tmp + 2, tc->link.base.num_lanes)));
/* Check link status */
ret = drm_dp_dpcd_read_link_status(aux, tmp);
if (ret < 0)
goto err_dpcd_read;
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]);
ret = 0;
return -EAGAIN;
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;