With this well documented we can remove that FIXME comment. We just need to make sure that on primary -> sprite transition there is no vblank time where ips gets alone on the pipe with absolutelly no plane. If this happens even for a quickly momment IPS won't get recovered and it might cause strange flickering screens.
Signed-off-by: Rodrigo Vivi <[email protected]> --- drivers/gpu/drm/i915/intel_display.c | 37 ++++++++++++++++++++++++------------ 1 file changed, 25 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 5519d56..d2c417b 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -4620,6 +4620,17 @@ static void intel_enable_sprite_planes(struct drm_crtc *crtc) } } +/** + * hsw_enable_ips - Enable IPS + * @intel_crtc: crtc + * + * This function needs to be called after there are at least on plane enabled + * on the pipe. + * + * IPS is fine as long as one plane is enabled. + * + * Pre-requisite: IPS cannot be enabled until after at least one plane has been enabled for at least one vertical blank. + */ void hsw_enable_ips(struct intel_crtc *crtc) { struct drm_device *dev = crtc->base.dev; @@ -4653,6 +4664,20 @@ void hsw_enable_ips(struct intel_crtc *crtc) } } +/** + * hsw_disable_ips - Disable IPS + * @intel_crtc: crtc + * + * This function needs to be called everytime that there will be no plane + * enabled on the pipe on the next vblank. + * + * IPS is fine as long as one plane is enabled, however it gets confused + * in a non recoverable state when it stays enabled on the pipe with no + * other plane enabled at same vblank time. So please make sure this + * function is called everytime that we have no plane enabled on the pipe. + * + * Pre-requisite: IPS must be disabled while there is still at least one plane enabled on the same pipe as IPS. + */ void hsw_disable_ips(struct intel_crtc *crtc) { struct drm_device *dev = crtc->base.dev; @@ -4769,12 +4794,6 @@ intel_post_enable_primary(struct drm_crtc *crtc) if (IS_BROADWELL(dev)) intel_wait_for_vblank(dev, pipe); - /* - * FIXME IPS should be fine as long as one plane is - * enabled, but in practice it seems to have problems - * when going from primary only to sprite only and vice - * versa. - */ hsw_enable_ips(intel_crtc); mutex_lock(&dev->struct_mutex); @@ -4840,12 +4859,6 @@ intel_pre_disable_primary(struct drm_crtc *crtc) intel_fbc_disable(dev); mutex_unlock(&dev->struct_mutex); - /* - * FIXME IPS should be fine as long as one plane is - * enabled, but in practice it seems to have problems - * when going from primary only to sprite only and vice - * versa. - */ hsw_disable_ips(intel_crtc); } -- 2.1.0 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
