From 0bf25146511334e5add88f6700aef4309b7e4b55 Mon Sep 17 00:00:00 2001 From: Tomi Valkeinen Date: Tue, 28 May 2019 11:27:38 +0300 Subject: [PATCH] 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: Tomi Valkeinen Reviewed-by: Andrzej Hajda Signed-off-by: Andrzej Hajda Link: https://patchwork.freedesktop.org/patch/msgid/20190528082747.3631-16-tomi.valkeinen@ti.com --- drivers/gpu/drm/bridge/tc358767.c | 62 ++++++++++++++++++++++----------------- 1 file changed, 35 insertions(+), 27 deletions(-) diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 40f3efcade50..d79b1d0ca0db 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -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]); - - 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; -- 2.11.0