From: zain wang wzz@rock-chips.com
We would meet a short black screen when exit PSR with the full link training, In this case, we should use fast link train instead of full link training.
Signed-off-by: zain wang wzz@rock-chips.com Signed-off-by: Sean Paul seanpaul@chromium.org Signed-off-by: Thierry Escande thierry.escande@collabora.com Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com Tested-by: Marek Szyprowski m.szyprowski@samsung.com ---
drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 142 ++++++++++++++++----- drivers/gpu/drm/bridge/analogix/analogix_dp_core.h | 3 + 2 files changed, 114 insertions(+), 31 deletions(-)
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index ee00d3d920e0..806c3878b3d6 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -10,17 +10,18 @@ * option) any later version. */
-#include <linux/module.h> -#include <linux/platform_device.h> -#include <linux/err.h> #include <linux/clk.h> -#include <linux/io.h> +#include <linux/component.h> +#include <linux/err.h> +#include <linux/gpio.h> #include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/module.h> #include <linux/of.h> #include <linux/of_gpio.h> -#include <linux/gpio.h> -#include <linux/component.h> #include <linux/phy/phy.h> +#include <linux/platform_device.h>
#include <drm/drmP.h> #include <drm/drm_atomic_helper.h> @@ -35,6 +36,8 @@
#define to_dp(nm) container_of(nm, struct analogix_dp_device, nm)
+static const bool verify_fast_training; + struct bridge_init { struct i2c_client *client; struct device_node *node; @@ -528,7 +531,7 @@ static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp) { int lane, lane_count, retval; u32 reg; - u8 link_align, link_status[2], adjust_request[2]; + u8 link_align, link_status[2], adjust_request[2], spread;
usleep_range(400, 401);
@@ -571,6 +574,20 @@ static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp) dev_dbg(dp->dev, "final lane count = %.2x\n", dp->link_train.lane_count);
+ retval = drm_dp_dpcd_readb(&dp->aux, DP_MAX_DOWNSPREAD, + &spread); + if (retval != 1) { + dev_err(dp->dev, "failed to read downspread %d\n", + retval); + dp->fast_train_support = false; + } else { + dp->fast_train_support = + (spread & DP_NO_AUX_HANDSHAKE_LINK_TRAINING) ? + true : false; + } + dev_dbg(dp->dev, "fast link training %s\n", + dp->fast_train_support ? "supported" : "unsupported"); + /* set enhanced mode if available */ analogix_dp_set_enhanced_mode(dp); dp->link_train.lt_state = FINISHED; @@ -627,10 +644,12 @@ static void analogix_dp_get_max_rx_lane_count(struct analogix_dp_device *dp, *lane_count = DPCD_MAX_LANE_COUNT(data); }
-static void analogix_dp_init_training(struct analogix_dp_device *dp, - enum link_lane_count_type max_lane, - int max_rate) +static int analogix_dp_full_link_train(struct analogix_dp_device *dp, + u32 max_lanes, u32 max_rate) { + int retval = 0; + bool training_finished = false; + /* * MACRO_RST must be applied after the PLL_LOCK to avoid * the DP inter pair skew issue for at least 10 us @@ -656,18 +675,13 @@ static void analogix_dp_init_training(struct analogix_dp_device *dp, }
/* Setup TX lane count & rate */ - if (dp->link_train.lane_count > max_lane) - dp->link_train.lane_count = max_lane; + if (dp->link_train.lane_count > max_lanes) + dp->link_train.lane_count = max_lanes; if (dp->link_train.link_rate > max_rate) dp->link_train.link_rate = max_rate;
/* All DP analog module power up */ analogix_dp_set_analog_power_down(dp, POWER_ALL, 0); -} - -static int analogix_dp_sw_link_training(struct analogix_dp_device *dp) -{ - int retval = 0, training_finished = 0;
dp->link_train.lt_state = START;
@@ -702,22 +716,88 @@ static int analogix_dp_sw_link_training(struct analogix_dp_device *dp) return retval; }
-static int analogix_dp_set_link_train(struct analogix_dp_device *dp, - u32 count, u32 bwtype) +static int analogix_dp_fast_link_train(struct analogix_dp_device *dp) { - int i; - int retval; + int i, ret; + u8 link_align, link_status[2]; + enum pll_status status;
- for (i = 0; i < DP_TIMEOUT_LOOP_COUNT; i++) { - analogix_dp_init_training(dp, count, bwtype); - retval = analogix_dp_sw_link_training(dp); - if (retval == 0) - break; + analogix_dp_reset_macro(dp); + + analogix_dp_set_link_bandwidth(dp, dp->link_train.link_rate); + analogix_dp_set_lane_count(dp, dp->link_train.lane_count);
- usleep_range(100, 110); + for (i = 0; i < dp->link_train.lane_count; i++) { + analogix_dp_set_lane_link_training(dp, + dp->link_train.training_lane[i], i); }
- return retval; + ret = readx_poll_timeout(analogix_dp_get_pll_lock_status, dp, status, + status != PLL_UNLOCKED, 120, + 120 * DP_TIMEOUT_LOOP_COUNT); + if (ret) { + DRM_DEV_ERROR(dp->dev, "Wait for pll lock failed %d\n", ret); + return ret; + } + + /* source Set training pattern 1 */ + analogix_dp_set_training_pattern(dp, TRAINING_PTN1); + /* From DP spec, pattern must be on-screen for a minimum 500us */ + usleep_range(500, 600); + + analogix_dp_set_training_pattern(dp, TRAINING_PTN2); + /* From DP spec, pattern must be on-screen for a minimum 500us */ + usleep_range(500, 600); + + /* TODO: enhanced_mode?*/ + analogix_dp_set_training_pattern(dp, DP_NONE); + + /* + * Useful for debugging issues with fast link training, disable for more + * speed + */ + if (verify_fast_training) { + ret = drm_dp_dpcd_readb(&dp->aux, DP_LANE_ALIGN_STATUS_UPDATED, + &link_align); + if (ret < 0) { + DRM_DEV_ERROR(dp->dev, "Read align status failed %d\n", + ret); + return ret; + } + + ret = drm_dp_dpcd_read(&dp->aux, DP_LANE0_1_STATUS, link_status, + 2); + if (ret < 0) { + DRM_DEV_ERROR(dp->dev, "Read link status failed %d\n", + ret); + return ret; + } + + if (analogix_dp_clock_recovery_ok(link_status, + dp->link_train.lane_count)) { + DRM_DEV_ERROR(dp->dev, "Clock recovery failed\n"); + analogix_dp_reduce_link_rate(dp); + return -EIO; + } + + if (analogix_dp_channel_eq_ok(link_status, link_align, + dp->link_train.lane_count)) { + DRM_DEV_ERROR(dp->dev, "Channel EQ failed\n"); + analogix_dp_reduce_link_rate(dp); + return -EIO; + } + } + + return 0; +} + +static int analogix_dp_train_link(struct analogix_dp_device *dp) +{ + if (dp->fast_train_support) + return analogix_dp_fast_link_train(dp); + + return analogix_dp_full_link_train(dp, dp->video_info.max_lane_count, + dp->video_info.max_link_rate); }
static int analogix_dp_config_video(struct analogix_dp_device *dp) @@ -846,10 +926,10 @@ static void analogix_dp_commit(struct analogix_dp_device *dp) DRM_ERROR("failed to disable the panel\n"); }
- ret = analogix_dp_set_link_train(dp, dp->video_info.max_lane_count, - dp->video_info.max_link_rate); + ret = readx_poll_timeout(analogix_dp_train_link, dp, ret, !ret, 100, + DP_TIMEOUT_TRAINING_US * 5); if (ret) { - dev_err(dp->dev, "unable to do link train\n"); + dev_err(dp->dev, "unable to do link train, ret=%d\n", ret); return; }
diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h index e135a42cb19e..920607d7eb3e 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h @@ -20,6 +20,8 @@ #define MAX_CR_LOOP 5 #define MAX_EQ_LOOP 5
+/* Training takes 22ms if AUX channel comm fails. Use this as retry interval */ +#define DP_TIMEOUT_TRAINING_US 22000 #define DP_TIMEOUT_PSR_LOOP_MS 300
/* DP_MAX_LANE_COUNT */ @@ -171,6 +173,7 @@ struct analogix_dp_device { int hpd_gpio; bool force_hpd; bool psr_enable; + bool fast_train_support;
struct mutex panel_lock; bool panel_is_modeset;