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

Sean,

Thanks for your comments.

On 09/07/2016 03:51 AM, Sean Paul wrote:

On Fri, Aug 26, 2016 at 6:19 AM, Yakir Yang ykk@rock-chips.com wrote:

...

Make sure the request PSR state could effect in analogix_dp_send_psr_spd() function, or printing the error Sink PSR state if we failed to effect the request PSR setting.

Signed-off-by: Yakir Yang ykk@rock-chips.com

drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 6 ++--- drivers/gpu/drm/bridge/analogix/analogix_dp_core.h | 4 ++-- drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c | 26 ++++++++++++++++++++-- 3 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index efac8ab..5a37de8 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -115,8 +115,7 @@ 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);

@@ -138,8 +137,7 @@ int analogix_dp_disable_psr(struct device *dev) psr_vsc.DB0 = 0; psr_vsc.DB1 = 0;

•   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 473b980..f617a9d 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.h @@ -283,7 +283,7 @@ 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);
  
  

  #endif /* _ANALOGIX_DP_CORE_H */

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c index 52c1b6b..505e9d8 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c @@ -1328,9 +1328,11 @@ 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)
  

+int analogix_dp_send_psr_spd(struct analogix_dp_device *dp,

•                        struct edp_vsc_psr *vsc)
  

  {

•   unsigned long timeout;
  

•   unsigned char sink;
  

u8

Done

...

     unsigned int val;

     /* don't send info frame */

@@ -1372,4 +1374,24 @@ 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);

•   timeout = jiffies + msecs_to_jiffies(100);
  

Pull 100 out into a #define

Done

...

•   while (1) {
  

•           analogix_dp_read_byte_from_dpcd(dp, DP_PSR_STATUS, &sink);
  

You should be checking return value here.

Done

...

•           if (vsc->DB1 && sink == DP_PSR_SINK_ACTIVE_RFB)
  

•                   break;
  

•           if (!vsc->DB1 && sink == DP_PSR_SINK_INACTIVE)
  

•                   break;
  

•           if (time_after(jiffies, timeout)) {
  

•                   dev_warn(dp->dev, "Failed to effect PSR: %x", sink);
  

•                   return -EBUSY;
  

-ETIMEDOUT is more appropriate

Done

...

•           }
  

•           usleep_range(1000, 1500);
  

•   }
  

The while(1) loop is a little scary. I'd rather do:

while (time_before(jiffies, timeout)) { ret = analogix_dp_read_byte_from_dpcd(dp, DP_PSR_STATUS, &sink); if (ret != 1) { DRM_DEV_ERROR(dp->dev, "PSR_STATUS read failed ret=%d", ret); return ret; }

            if (vsc->DB1 && sink == DP_PSR_SINK_ACTIVE_RFB ||
                !vsc->DB1 && sink == DP_PSR_SINK_INACTIVE)
                    return 0;

            usleep_range(1000, 1500);

}

dev_warn(dp->dev, "Failed to effect PSR: %x", sink); return -ETIMEDOUT;

Thanks for your code.

- Yakir

...

•   return 0;
  

  }

-- 1.9.1

-- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html