lontium-lt9611: check a different register bit for HDMI sensing

It has been observed that with certain monitors such as the HP Z27n,
the register 0x825e reads a value of 0x79 when the HDMI cable is
connected and 0x78 when it is disconnected, i.e. bit 0 appears
to correspond to the HDMI connection status and bit 2 is never
set. Therefore, change the driver to check bit 0 instead of bit 2.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/I7e76411127e1ce4988a3f6d0c8ba5f1c3d880c23
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211117020724.2647769-1-pcc@google.com

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c
index d2f45a0f79c83cbadd17bbbf17c7a60a7e1f4562..dafb1b47c15fb2d7d6b774b45c66d5e8041280b7 100644 (file)
--- a/drivers/gpu/drm/bridge/lontium-lt9611.c
+++ b/drivers/gpu/drm/bridge/lontium-lt9611.c
@@ -586,7 +586,7 @@ lt9611_connector_detect(struct drm_connector *connector, bool force)
        int connected = 0;
 
        regmap_read(lt9611->regmap, 0x825e, &reg_val);
-       connected  = (reg_val & BIT(2));
+       connected  = (reg_val & BIT(0));
 
        lt9611->status = connected ?  connector_status_connected :
                                connector_status_disconnected;
@@ -892,7 +892,7 @@ static enum drm_connector_status lt9611_bridge_detect(struct drm_bridge *bridge)
        int connected;
 
        regmap_read(lt9611->regmap, 0x825e, &reg_val);
-       connected  = reg_val & BIT(2);
+       connected  = reg_val & BIT(0);
 
        lt9611->status = connected ?  connector_status_connected :
                                connector_status_disconnected;