From: Zhao Yakui Date: Wed, 9 Dec 2009 03:23:42 +0000 (+0800) Subject: drm: disable all the possible outputs/crtcs before entering KMS mode X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b16d9acbdb97452d1418420e069acf7381ef10bb;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git drm: disable all the possible outputs/crtcs before entering KMS mode Sometimes we will use a crtc for integerated LVDS, which is different with that assigned by BIOS. If we want to get flicker-free transitions, then we could read out the current state for it and set our current state accordingly. But it is true that if we aren't reading current state out, we do need to turn everything off before modesetting. Otherwise the clocks can get very angry and we get things worse than a flicker at boot. In fact we also do the similar thing in UMS mode. We will disable all the possible outputs/crtcs for the first modesetting. So we disable all the possible outputs/crtcs before entering the KMS mode. Before we configure connector/encoder/crtc, the function of drm_helper_disable_unused_function can disable all the possible outputs/crtcs. Signed-off-by: Zhao Yakui Reviewed-by: Eric Anholt Reviewed-by: Rafal Milecki Signed-off-by: Dave Airlie --- diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index 3963b3c1081a..4231d6db72ec 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -1020,6 +1020,9 @@ bool drm_helper_initial_config(struct drm_device *dev) { int count = 0; + /* disable all the possible outputs/crtcs before entering KMS mode */ + drm_helper_disable_unused_functions(dev); + drm_fb_helper_parse_command_line(dev); count = drm_helper_probe_connector_modes(dev,