gfx: display: tc35876x: disable flopped high-speed transmitting path

The flopped high-speed transmitting path was (for reasons unknown) enabled
in the MIPIA_PORT_CTRL register for tc35876x. This caused visible noise on
screen in certain RGB values, typically at ~90% of the full color
intensity, on some devices. Disable the feature.

Issue: ANDROID-1865
Issue: GRA-6
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

diff --git a/drivers/staging/mrst/drv/mdfld_dsi_dpi.c b/drivers/staging/mrst/drv/mdfld_dsi_dpi.c
index 664f283..f8c19d5 100644 (file)
--- a/drivers/staging/mrst/drv/mdfld_dsi_dpi.c
+++ b/drivers/staging/mrst/drv/mdfld_dsi_dpi.c
@@ -927,7 +927,7 @@ void mdfld_dsi_dpi_mode_set(struct drm_encoder * encoder,
                REG_WRITE(VGACNTRL, 0x80000000);
                REG_WRITE(DEVICE_READY_REG, 0x00000001);
 
-               REG_WRITE(MIPI_PORT_CONTROL(pipe), 0x80810000);
+               REG_WRITE(MIPI_PORT_CONTROL(pipe), BIT(31) | BIT(16));
        } else {
                /*set up mipi port FIXME: do at init time */
                REG_WRITE(MIPI_PORT_CONTROL(pipe), mipi);