[PATCH v12 01/16] drm/bridge: dw-hdmi-qp: Demote i2c bus error messages to debug level

[Cristian Ciocaltea]

A NACK or timeout on the DDC bus is a normal condition when the sink is
absent or unpowered.  Some displays keep HPD asserted and the EDID
EEPROM readable while in standby, but leave the SCDC slave unpowered.
This results in i2c-related error messages on every boot during
scrambling setup, even though the condition is handled gracefully and
the SCDC configuration is restored on the next hotplug event.

Log the i2c bus level failures with dev_dbg_ratelimited() instead,
matching the silent behaviour of the non-QP dw-hdmi i2c bus algorithm.
The DDC users already report failures at the appropriate level, e.g. the
SCDC helpers via drm_scdc_dbg().  This also makes the no-hpd special
casing of the read path messages redundant, so drop it.

Reported-by: Diederik de Haas <diederik@xxxxxxxxxxxxxx>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
index c9568aea98dc..9abcea92b720 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-qp.c
@@ -350,22 +350,14 @@ static int dw_hdmi_qp_i2c_read(struct dw_hdmi_qp *hdmi,
 
 		stat = wait_for_completion_timeout(&i2c->cmp, HZ / 10);
 		if (!stat) {
-			if (hdmi->no_hpd)
-				dev_dbg_ratelimited(hdmi->dev,
-						    "i2c read timed out\n");
-			else
-				dev_err(hdmi->dev, "i2c read timed out\n");
+			dev_dbg_ratelimited(hdmi->dev, "i2c read timed out\n");
 			dw_hdmi_qp_write(hdmi, 0x01, I2CM_CONTROL0);
 			return -EAGAIN;
 		}
 
 		/* Check for error condition on the bus */
 		if (i2c->stat & I2CM_NACK_RCVD_IRQ) {
-			if (hdmi->no_hpd)
-				dev_dbg_ratelimited(hdmi->dev,
-						    "i2c read error\n");
-			else
-				dev_err(hdmi->dev, "i2c read error\n");
+			dev_dbg_ratelimited(hdmi->dev, "i2c read error\n");
 			dw_hdmi_qp_write(hdmi, 0x01, I2CM_CONTROL0);
 			return -EIO;
 		}
@@ -404,14 +396,14 @@ static int dw_hdmi_qp_i2c_write(struct dw_hdmi_qp *hdmi,
 
 		stat = wait_for_completion_timeout(&i2c->cmp, HZ / 10);
 		if (!stat) {
-			dev_err(hdmi->dev, "i2c write time out!\n");
+			dev_dbg_ratelimited(hdmi->dev, "i2c write time out!\n");
 			dw_hdmi_qp_write(hdmi, 0x01, I2CM_CONTROL0);
 			return -EAGAIN;
 		}
 
 		/* Check for error condition on the bus */
 		if (i2c->stat & I2CM_NACK_RCVD_IRQ) {
-			dev_err(hdmi->dev, "i2c write nack!\n");
+			dev_dbg_ratelimited(hdmi->dev, "i2c write nack!\n");
 			dw_hdmi_qp_write(hdmi, 0x01, I2CM_CONTROL0);
 			return -EIO;
 		}

-- 
2.55.0