[PATCH v3 22/43] drm/bridge: analogix_dp: Check dpcd write/read status

Thierry Escande
2018-01-30T20:35:46Z

From: Lin Huang <hl@rock-chips.com>

We need to check the dpcd write/read return value to see whether the
write/read was successful

Cc: Kristian H. Kristensen <hoegsberg@chromium.org>
Signed-off-by: Lin Huang <hl@rock-chips.com>
Signed-off-by: zain wang <wzz@rock-chips.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
---
drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 182 +++++++++++++++------
1 file changed, 135 insertions(+), 47 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 846574d0dcb0..082b4e024052 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -160,80 +160,137 @@ int analogix_dp_disable_psr(struct analogix_dp_device *dp)
}
EXPORT_SYMBOL_GPL(analogix_dp_disable_psr);

-static bool analogix_dp_detect_sink_psr(struct analogix_dp_device *dp)
+static int analogix_dp_detect_sink_psr(struct analogix_dp_device *dp)
{
unsigned char psr_version;
+ int ret;
+
+ ret = drm_dp_dpcd_readb(&dp->aux, DP_PSR_SUPPORT, &psr_version);
+ if (ret != 1) {
+ dev_err(dp->dev, "failed to get PSR version, disable it\n");
+ return ret;
+ }

- drm_dp_dpcd_readb(&dp->aux, DP_PSR_SUPPORT, &psr_version);
dev_dbg(dp->dev, "Panel PSR version : %x\n", psr_version);

- return (psr_version & DP_PSR_IS_SUPPORTED) ? true : false;
+ dp->psr_enable = (psr_version & DP_PSR_IS_SUPPORTED) ? true : false;
+
+ return 0;
}

-static void analogix_dp_enable_sink_psr(struct analogix_dp_device *dp)
+static int analogix_dp_enable_sink_psr(struct analogix_dp_device *dp)
{
unsigned char psr_en;
+ int ret;

/* Disable psr function */
- drm_dp_dpcd_readb(&dp->aux, DP_PSR_EN_CFG, &psr_en);
+ ret = drm_dp_dpcd_readb(&dp->aux, DP_PSR_EN_CFG, &psr_en);
+ if (ret != 1) {
+ dev_err(dp->dev, "failed to get psr config\n");
+ goto end;
+ }
+
psr_en &= ~DP_PSR_ENABLE;
- drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
+ ret = drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
+ if (ret != 1) {
+ dev_err(dp->dev, "failed to disable panel psr\n");
+ goto end;
+ }

/* Main-Link transmitter remains active during PSR active states */
psr_en = DP_PSR_MAIN_LINK_ACTIVE | DP_PSR_CRC_VERIFICATION;
- drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
+ ret = drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
+ if (ret != 1) {
+ dev_err(dp->dev, "failed to set panel psr\n");
+ goto end;
+ }

/* Enable psr function */
psr_en = DP_PSR_ENABLE | DP_PSR_MAIN_LINK_ACTIVE |
DP_PSR_CRC_VERIFICATION;
- drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
+ ret = drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
+ if (ret != 1) {
+ dev_err(dp->dev, "failed to set panel psr\n");
+ goto end;
+ }

analogix_dp_enable_psr_crc(dp);
+
+ return 0;
+end:
+ dev_err(dp->dev, "enable psr fail, force to disable psr\n");
+ dp->psr_enable = false;
+
+ return ret;
}

-static void
+static int
analogix_dp_enable_rx_to_enhanced_mode(struct analogix_dp_device *dp,
bool enable)
{
u8 data;
+ int ret;

- drm_dp_dpcd_readb(&dp->aux, DP_LANE_COUNT_SET, &data);
+ ret = drm_dp_dpcd_readb(&dp->aux, DP_LANE_COUNT_SET, &data);
+ if (ret != 1)
+ return ret;

if (enable)
- drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET,
- DP_LANE_COUNT_ENHANCED_FRAME_EN |
- DPCD_LANE_COUNT_SET(data));
+ ret = drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET,
+ DP_LANE_COUNT_ENHANCED_FRAME_EN |
+ DPCD_LANE_COUNT_SET(data));
else
- drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET,
- DPCD_LANE_COUNT_SET(data));
+ ret = drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET,
+ DPCD_LANE_COUNT_SET(data));
+
+ return ret < 0 ? ret : 0;
}

-static int analogix_dp_is_enhanced_mode_available(struct analogix_dp_device *dp)
+static int analogix_dp_is_enhanced_mode_available(struct analogix_dp_device *dp,
+ u8 *enhanced_mode_support)
{
u8 data;
- int retval;
+ int ret;

- drm_dp_dpcd_readb(&dp->aux, DP_MAX_LANE_COUNT, &data);
- retval = DPCD_ENHANCED_FRAME_CAP(data);
+ ret = drm_dp_dpcd_readb(&dp->aux, DP_MAX_LANE_COUNT, &data);
+ if (ret != 1) {
+ *enhanced_mode_support = 0;
+ return ret;
+ }

- return retval;
+ *enhanced_mode_support = DPCD_ENHANCED_FRAME_CAP(data);
+
+ return 0;
}

-static void analogix_dp_set_enhanced_mode(struct analogix_dp_device *dp)
+static int analogix_dp_set_enhanced_mode(struct analogix_dp_device *dp)
{
u8 data;
+ int ret;
+
+ ret = analogix_dp_is_enhanced_mode_available(dp, &data);
+ if (ret < 0)
+ return ret;
+
+ ret = analogix_dp_enable_rx_to_enhanced_mode(dp, data);
+ if (ret < 0)
+ return ret;

- data = analogix_dp_is_enhanced_mode_available(dp);
- analogix_dp_enable_rx_to_enhanced_mode(dp, data);
analogix_dp_enable_enhanced_mode(dp, data);
+
+ return 0;
}

-static void analogix_dp_training_pattern_dis(struct analogix_dp_device *dp)
+static int analogix_dp_training_pattern_dis(struct analogix_dp_device *dp)
{
+ int ret;
+
analogix_dp_set_training_pattern(dp, DP_NONE);

- drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
- DP_TRAINING_PATTERN_DISABLE);
+ ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
+ DP_TRAINING_PATTERN_DISABLE);
+
+ return ret < 0 ? ret : 0;
}

static void
@@ -282,7 +339,11 @@ static int analogix_dp_link_start(struct analogix_dp_device *dp)
if (retval < 0)
return retval;
/* set enhanced mode if available */
- analogix_dp_set_enhanced_mode(dp);
+ retval = analogix_dp_set_enhanced_mode(dp);
+ if (retval < 0) {
+ dev_err(dp->dev, "failed to set enhance mode\n");
+ return retval;
+ }

/* Set TX pre-emphasis to minimum */
for (lane = 0; lane < lane_count; lane++)
@@ -567,10 +628,11 @@ static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp)

if (!analogix_dp_channel_eq_ok(link_status, link_align, lane_count)) {
/* traing pattern Set to Normal */
- analogix_dp_training_pattern_dis(dp);
+ retval = analogix_dp_training_pattern_dis(dp);
+ if (retval < 0)
+ return retval;

dev_info(dp->dev, "Link Training success!\n");
-
analogix_dp_get_link_bandwidth(dp, &reg);
dp->link_train.link_rate = reg;
dev_dbg(dp->dev, "final bandwidth = %.2x\n",
@@ -807,7 +869,6 @@ static int analogix_dp_train_link(struct analogix_dp_device *dp)

static int analogix_dp_config_video(struct analogix_dp_device *dp)
{
- int retval = 0;
int timeout_loop = 0;
int done_count = 0;

@@ -865,30 +926,42 @@ static int analogix_dp_config_video(struct analogix_dp_device *dp)
usleep_range(1000, 1001);
}

- if (retval != 0)
- dev_err(dp->dev, "Video stream is not detected!\n");
-
- return retval;
+ return 0;
}

-static void analogix_dp_enable_scramble(struct analogix_dp_device *dp,
- bool enable)
+static int analogix_dp_enable_scramble(struct analogix_dp_device *dp,
+ bool enable)
{
u8 data;
+ int ret;

if (enable) {
analogix_dp_enable_scrambling(dp);

- drm_dp_dpcd_readb(&dp->aux, DP_TRAINING_PATTERN_SET, &data);
- drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
+ ret = drm_dp_dpcd_readb(&dp->aux, DP_TRAINING_PATTERN_SET,
+ &data);
+ if (ret != 1)
+ return ret;
+
+ ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
(u8)(data & ~DP_LINK_SCRAMBLING_DISABLE));
+ if (ret < 0)
+ return ret;
} else {
analogix_dp_disable_scrambling(dp);

- drm_dp_dpcd_readb(&dp->aux, DP_TRAINING_PATTERN_SET, &data);
- drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
+ ret = drm_dp_dpcd_readb(&dp->aux, DP_TRAINING_PATTERN_SET,
+ &data);
+ if (ret != 1)
+ return ret;
+
+ ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
(u8)(data | DP_LINK_SCRAMBLING_DISABLE));
+ if (ret < 0)
+ return ret;
}
+
+ return 0;
}

static irqreturn_t analogix_dp_hardirq(int irq, void *arg)
@@ -943,23 +1016,36 @@ static int analogix_dp_commit(struct analogix_dp_device *dp)
return ret;
}

- analogix_dp_enable_scramble(dp, 1);
+ ret = analogix_dp_enable_scramble(dp, 1);
+ if (ret < 0) {
+ dev_err(dp->dev, "can not enable scramble\n");
+ return ret;
+ }

analogix_dp_init_video(dp);
ret = analogix_dp_config_video(dp);
- if (ret)
+ if (ret) {
dev_err(dp->dev, "unable to config video\n");
+ return ret;
+ }

/* Safe to enable the panel now */
if (dp->plat_data->panel) {
- if (drm_panel_enable(dp->plat_data->panel))
+ ret = drm_panel_enable(dp->plat_data->panel);
+ if (ret) {
DRM_ERROR("failed to enable the panel\n");
+ return ret;
+ }
}

- dp->psr_enable = analogix_dp_detect_sink_psr(dp);
+ ret = analogix_dp_detect_sink_psr(dp);
+ if (ret)
+ return ret;
+
if (dp->psr_enable)
- analogix_dp_enable_sink_psr(dp);
- return 0;
+ ret = analogix_dp_enable_sink_psr(dp);
+
+ return ret;
}

/*
@@ -1186,8 +1272,10 @@ static int analogix_dp_set_bridge(struct analogix_dp_device *dp)
}

ret = analogix_dp_commit(dp);
- if (ret)
+ if (ret) {
+ DRM_ERROR("dp commit error, ret = %d\n", ret);
goto out_dp_init;
+ }

enable_irq(dp->irq);
return 0;
--
2.14.1