[PATCH v2 22/43] drm/bridge: analogix_dp: Check dpcd write/read status
Sean Paul
seanpaul at chromium.org
Mon Jan 29 13:14:41 PST 2018
On Fri, Jan 26, 2018 at 02:16:49PM +0100, Thierry Escande wrote:
> From: Lin Huang <hl at 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 at chromium.org>
> Signed-off-by: Lin Huang <hl at rock-chips.com>
> Signed-off-by: zain wang <wzz at rock-chips.com>
> Signed-off-by: Douglas Anderson <dianders at chromium.org>
> Signed-off-by: Sean Paul <seanpaul at chromium.org>
> Signed-off-by: Thierry Escande <thierry.escande at collabora.com>
> Reviewed-by: Andrzej Hajda <a.hajda at samsung.com>
> ---
> drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 181 +++++++++++++++------
> 1 file changed, 132 insertions(+), 49 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..501f7b4a23d6 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -160,80 +160,135 @@ 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 < 0)
> + 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 < 0)
Above we check for ret != 1, so we should probably stay consistent. Same nit
throughout the patch.
> + 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 retval;
Above we're replacing retval with ret, however here we introduce retval.
> +
> analogix_dp_set_training_pattern(dp, DP_NONE);
>
> - drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
> - DP_TRAINING_PATTERN_DISABLE);
> + retval = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
> + DP_TRAINING_PATTERN_DISABLE);
> +
> + return retval < 0 ? retval : 0;
> }
>
> static void
> @@ -282,7 +337,11 @@ 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 +626,11 @@ 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, ®);
> dp->link_train.link_rate = reg;
> dev_dbg(dp->dev, "final bandwidth = %.2x\n",
> @@ -807,7 +867,6 @@ 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;
>
> @@ -825,8 +884,9 @@ static int analogix_dp_config_video(struct analogix_dp_device *dp)
> if (analogix_dp_is_slave_video_stream_clock_on(dp) == 0)
> break;
> if (timeout_loop > DP_TIMEOUT_LOOP_COUNT) {
> - dev_err(dp->dev, "Timeout of slave video streamclk ok\n");
> - return -ETIMEDOUT;
> + dev_warn(dp->dev,
> + "Ignoring timeout of slave video streamclk ok\n");
> + break;
This change has sort of snuck in here. It doesn't seem related to the change,
but maybe I'm overlooking something.
> }
> usleep_range(1000, 1001);
Unrelated: This is pretty hilarious.
> }
> @@ -865,30 +925,38 @@ 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));
> } 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));
This should probably be explicitly checked as well, since the inline conditional
in the return isn't checking what the rest of the function is.
> }
> +
> + return ret < 0 ? ret : 0;
> }
>
> static irqreturn_t analogix_dp_hardirq(int irq, void *arg)
> @@ -943,23 +1011,36 @@ 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 +1267,10 @@ 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
>
--
Sean Paul, Software Engineer, Google / Chromium OS
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