[PATCH 08/41] drm/bridge: analogix_dp: detect Sink PSR state after configuring the PSR

[Andrzej Hajda]

On 10.03.2017 05:32, Sean Paul wrote:
> From: Yakir Yang <ykk at rock-chips.com>
>
> Make sure the request PSR state takes effect in analogix_dp_send_psr_spd()
> function, or print the sink PSR error state if we failed to apply the
> requested PSR setting.
>
> Cc: 征增 王 <wzz at rock-chips.com>
> Cc: Stéphane Marchesin <marcheu at chromium.org>
> Signed-off-by: Yakir Yang <ykk at rock-chips.com>
> [seanpaul changed timeout loop to a readx poll]
> Signed-off-by: Sean Paul <seanpaul at chromium.org>
> ---
>  drivers/gpu/drm/bridge/analogix/analogix_dp_core.c |  6 ++--
>  drivers/gpu/drm/bridge/analogix/analogix_dp_core.h |  6 ++--
>  drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c  | 35 +++++++++++++++++++---
>  3 files changed, 37 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> index f64592f52262..8a8f05fe9da3 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> @@ -124,8 +124,7 @@ int analogix_dp_enable_psr(struct device *dev)
>  	psr_vsc.DB0 = 0;
>  	psr_vsc.DB1 = EDP_VSC_PSR_STATE_ACTIVE | EDP_VSC_PSR_CRC_VALUES_VALID;
>  
> -	analogix_dp_send_psr_spd(dp, &psr_vsc);
> -	return 0;
> +	return analogix_dp_send_psr_spd(dp, &psr_vsc);
>  }
>  EXPORT_SYMBOL_GPL(analogix_dp_enable_psr);
>  
> @@ -152,8 +151,7 @@ int analogix_dp_disable_psr(struct device *dev)
>  	if (ret != 1)
>  		dev_err(dp->dev, "Failed to set DP Power0 %d\n", ret);
>  
> -	analogix_dp_send_psr_spd(dp, &psr_vsc);
> -	return 0;
> +	return analogix_dp_send_psr_spd(dp, &psr_vsc);
>  }
>  EXPORT_SYMBOL_GPL(analogix_dp_disable_psr);
>  
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h
> index 5c6a28806129..b039b28d8fcc 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
>  
> +#define DP_TIMEOUT_PSR_LOOP_MS			300
> +
>  /* DP_MAX_LANE_COUNT */
>  #define DPCD_ENHANCED_FRAME_CAP(x)		(((x) >> 7) & 0x1)
>  #define DPCD_MAX_LANE_COUNT(x)			((x) & 0x1f)
> @@ -247,8 +249,8 @@ void analogix_dp_config_video_slave_mode(struct analogix_dp_device *dp);
>  void analogix_dp_enable_scrambling(struct analogix_dp_device *dp);
>  void analogix_dp_disable_scrambling(struct analogix_dp_device *dp);
>  void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp);
> -void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
> -			      struct edp_vsc_psr *vsc);
> +int analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
> +			     struct edp_vsc_psr *vsc);
>  ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,
>  			     struct drm_dp_aux_msg *msg);
>  
> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> index 303083ad28e3..005a3f7005d2 100644
> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
> @@ -10,10 +10,11 @@
>   * option) any later version.
>   */
>  
> -#include <linux/device.h>
> -#include <linux/io.h>
>  #include <linux/delay.h>
> +#include <linux/device.h>
>  #include <linux/gpio.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
>  
>  #include <drm/bridge/analogix_dp.h>
>  
> @@ -992,10 +993,25 @@ void analogix_dp_enable_psr_crc(struct analogix_dp_device *dp)
>  	writel(PSR_VID_CRC_ENABLE, dp->reg_base + ANALOGIX_DP_CRC_CON);
>  }
>  
> -void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
> -			      struct edp_vsc_psr *vsc)
> +static ssize_t analogix_dp_get_psr_status(struct analogix_dp_device *dp)
> +{
> +	ssize_t val;
> +	u8 status;
> +
> +	val = drm_dp_dpcd_readb(&dp->aux, DP_PSR_STATUS, &status);
> +	if (val < 0) {
> +		dev_err(dp->dev, "PSR_STATUS read failed ret=%zd", val);

missing "\n"

> +		return val;
> +	}
> +	return status;
> +}
> +
> +int analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
> +			     struct edp_vsc_psr *vsc)
>  {
>  	unsigned int val;
> +	int ret;
> +	ssize_t psr_status;
>  
>  	/* don't send info frame */
>  	val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
> @@ -1036,6 +1052,17 @@ void analogix_dp_send_psr_spd(struct analogix_dp_device *dp,
>  	val = readl(dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
>  	val |= IF_EN;
>  	writel(val, dp->reg_base + ANALOGIX_DP_PKT_SEND_CTL);
> +
> +	ret = readx_poll_timeout(analogix_dp_get_psr_status, dp, psr_status,
> +		psr_status >= 0 &&
> +		((vsc->DB1 && psr_status == DP_PSR_SINK_ACTIVE_RFB) ||
> +		(!vsc->DB1 && psr_status == DP_PSR_SINK_INACTIVE)), 1500,
> +		DP_TIMEOUT_PSR_LOOP_MS * 1000);

As I understand you want to repeat read even in case
analogix_dp_get_psr_status fails?

I guess vsc->DB1 is constant, in such case you can shorten this complex
condition, by evaluating expected value before:
    val = vsc->DB1 ? DP_PSR_SINK_ACTIVE_RFB : DP_PSR_SINK_INACTIVE;
    ret = readx_poll_timeout(..., psr_status == val, ...

> +	if (ret) {
> +		dev_warn(dp->dev, "Failed to apply PSR %d\n", ret);

Maybe comma after PSR.

Regards
Andrzej


> +		return ret;
> +	}
> +	return 0;
>  }
>  
>  ssize_t analogix_dp_transfer(struct analogix_dp_device *dp,