[Intel-gfx] [PATCH 2/2] uxa: Mark the output as off before making pipe changes

[Hans de Goede]

This is a partial "backport" of commit c6cd10f536, which makes the same
change for sna, to avoid users still using uxa ending up with a blackscreen
after plugging in an external monitor.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
 src/uxa/intel_display.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/uxa/intel_display.c b/src/uxa/intel_display.c
index e00b9c2..a745dc5 100644
--- a/src/uxa/intel_display.c
+++ b/src/uxa/intel_display.c
@@ -320,6 +320,14 @@ intel_crtc_apply(xf86CrtcPtr crtc)
 		xf86OutputPtr output = xf86_config->output[i];
 		struct intel_output *intel_output;
 
+		/* Make sure we mark the output as off (and save the backlight)
+		 * before the kernel turns it off due to changing the pipe.
+		 * This is necessary as the kernel may turn off the backlight
+		 * and we lose track of the user settings.
+		 */
+		if (output->crtc == NULL)
+			output->funcs->dpms(output, DPMSModeOff);
+
 		if (output->crtc != crtc)
 			continue;
 
-- 
2.0.0