Re: [PATCH v5 16/36] drm/bridge: analogix_dp: Check dpcd write/read status

Archit Taneja
2018-03-14T06:19:17Z

On Saturday 10 March 2018 03:53 AM, Enric Balletbo i Serra wrote:
> 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
>

Reviewed-by: Archit Taneja <architt@codeaurora.org>

Thanks,
Archit

> 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>
> 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 | 169 ++++++++++++++++-----
> 1 file changed, 127 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index 1eed35f9eb8d..be6eddd0d0a7 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",
> @@ -867,24 +929,32 @@ static int analogix_dp_config_video(struct analogix_dp_device *dp)
> 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));
> }
> + return ret < 0 ? ret : 0;
> }
>
> static irqreturn_t analogix_dp_hardirq(int irq, void *arg)
> @@ -939,23 +1009,36 @@ 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;
> }
>
> /*
> @@ -1185,8 +1268,10 @@ 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;
>
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