On Thu, 3 Feb 2011 16:30:56 -0800, Linus Torvalds wrote: > On Thu, Feb 3, 2011 at 4:06 PM, Dave Airlie wrote: > > > > If we are setting a mode on a connector it automatically will end up > > in a DPMS on state, > > so this seemed correct from what I can see. > > The more I look at that function, the more I disagree with you and > with that patch. > > The code is just crazy. > > First off, it isn't even necessarily setting a mode to begin with, > because as far as I can tell. If the mode doesn't change, neither > mode_changed nor fb_changed will be true, afaik. There seems to be a > fair amount of code there explicitly to avoid changing modes if not > necessary. > > But even _if_ we are setting a mode, if I read the code correctly, the > mode may be set to NULL - which seems to mean "turn it off". In which > case it looks to me that drm_helper_disable_unused_functions() will > actually do a > > (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF); > > call on the crtc in question. So then blindly just saying "it's mode > DRM_MODE_DPMS_ON" afterwards looks rather bogus to me. > > _Maybe_ it would work if it was done before that whole > "disable_unused" logic. Or maybe it should just be done in > drm_crtc_helper_set_mode(), which is what actually sets the mode (but > there's the 'fb_changed' case too) > > > A future mode set shouldn't ever not turn the connector on, since > > modesetting is an implicit > > DPMS, > > > > It sounds like something more subtle than that, though I'm happy to > > revert this for now, and let Keith > > think about it a bit more. > > So I haven't heard anything from Keith. Keith? Just revert it? Or do > you have a patch for people to try? The goal is to make it so that when you *do* set a mode, DPMS gets set to ON (as the monitor will actually be "on" at that point). Here's a patch which does the DPMS_ON precisely when setting a mode. Dave thinks we should instead force dpms to match crtc->enabled, I'd rather have dpms get set when we know the hardware has been changed. (note, this patch compiles, but is otherwise only lightly tested). From 38507bb3a67441425e11085d17d727f3b230f927 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Thu, 3 Feb 2011 16:57:28 -0800 Subject: [PATCH] drm: Only set DPMS ON when actually configuring a mode In drm_crtc_helper_set_config, instead of always forcing all outputs to DRM_MODE_DPMS_ON, only set them if the CRTC is actually getting a mode set, as any mode set will turn all outputs on. Signed-off-by: Keith Packard --- drivers/gpu/drm/drm_crtc_helper.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index 952b3d4..17459ee 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -665,6 +665,12 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set) ret = -EINVAL; goto fail; } + DRM_DEBUG_KMS("Setting connector DPMS state to on\n"); + for (i = 0; i < set->num_connectors; i++) { + DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id, + drm_get_connector_name(set->connectors[i])); + set->connectors[i]->dpms = DRM_MODE_DPMS_ON; + } } drm_helper_disable_unused_functions(dev); } else if (fb_changed) { @@ -681,12 +687,6 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set) goto fail; } } - DRM_DEBUG_KMS("Setting connector DPMS state to on\n"); - for (i = 0; i < set->num_connectors; i++) { - DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id, - drm_get_connector_name(set->connectors[i])); - set->connectors[i]->dpms = DRM_MODE_DPMS_ON; - } kfree(save_connectors); kfree(save_encoders); -- 1.7.2.3 -- keith.packard@intel.com