From 5be19d910b9fc40102af475b3d1e6f2e0e9770d5 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 9 Oct 2013 10:47:12 +0200 Subject: [PATCH] drm/i915/lvds: don't restore hw state in the lid notifier for pch platforms It's a pain for two reasons: - The vga plane redisablign requires actual legacy vgao i/o to pull of. The hw engineers really botched this one here :( - There seem to be some BIOS out there which send out lid events when unplugging. Together with our broken DP code, which disables the port when the cable is lost, this results in an immediate modeset call, which can hang on the wait for outstanding flips. - Also we don't want to force a modeset on machines where it's not really needed, see the referenced bug. We might want to extend this in general to also all machines that support opregion, since there the BIOS supposedly should manage the gfx hardware more cooperatively. v2: Pimp commit message a bit. Cc: Roland Dreier References: https://bugs.freedesktop.org/show_bug.cgi?id=65486 Acked-by: Chris Wilson Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_lvds.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c index 3deb58e2f394..4c8553ea82f7 100644 --- a/drivers/gpu/drm/i915/intel_lvds.c +++ b/drivers/gpu/drm/i915/intel_lvds.c @@ -447,9 +447,19 @@ static int intel_lid_notify(struct notifier_block *nb, unsigned long val, if (dev_priv->modeset_restore == MODESET_DONE) goto exit; - drm_modeset_lock_all(dev); - intel_modeset_setup_hw_state(dev, true); - drm_modeset_unlock_all(dev); + /* + * Some old platform's BIOS love to wreak havoc while the lid is closed. + * We try to detect this here and undo any damage. The split for PCH + * platforms is rather conservative and a bit arbitrary expect that on + * those platforms VGA disabling requires actual legacy VGA I/O access, + * and as part of the cleanup in the hw state restore we also redisable + * the vga plane. + */ + if (!HAS_PCH_SPLIT(dev)) { + drm_modeset_lock_all(dev); + intel_modeset_setup_hw_state(dev, true); + drm_modeset_unlock_all(dev); + } dev_priv->modeset_restore = MODESET_DONE; -- 2.20.1