From 279e99d76e6097ee7b531114777fa9b030496d81 Mon Sep 17 00:00:00 2001 From: Matt Roper Date: Thu, 12 May 2016 07:06:02 -0700 Subject: [PATCH] drm/i915: Add distrust_bios_wm flag to dev_priv (v2) SKL-style platforms can't fully trust the watermark/DDB settings programmed by the BIOS and need to do extra sanitization on their first atomic update. Add a flag to dev_priv that is set during hardware readout and cleared at the end of the first commit. Note that for the somewhat common case where everything is turned off when the driver starts up, we don't need to bother with a recompute...we know exactly what the DDB should be (all zero's) so just setup the DDB directly in that case. v2: - Move clearing of distrust_bios_wm up below the swap_state call since it's a more natural / self-explanatory location. (Maarten) - Use dev_priv->active_crtcs to test whether any CRTC's are turned on during HW WM readout rather than trying to count the active CRTC's again ourselves. (Maarten) Cc: Maarten Lankhorst Signed-off-by: Matt Roper Reviewed-by: Maarten Lankhorst Link: http://patchwork.freedesktop.org/patch/msgid/1463061971-19638-9-git-send-email-matthew.d.roper@intel.com --- drivers/gpu/drm/i915/i915_drv.h | 7 +++++++ drivers/gpu/drm/i915/intel_display.c | 1 + drivers/gpu/drm/i915/intel_pm.c | 8 ++++++++ 3 files changed, 16 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index fb7fd7de2b76..985defce9908 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1995,6 +1995,13 @@ struct drm_i915_private { * cstate->wm.need_postvbl_update. */ struct mutex wm_mutex; + + /* + * Set during HW readout of watermarks/DDB. Some platforms + * need to know when we're still using BIOS-provided values + * (which we don't fully trust). + */ + bool distrust_bios_wm; } wm; struct i915_runtime_pm pm; diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 5d9909049180..102320c7f3b7 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -13594,6 +13594,7 @@ static int intel_atomic_commit(struct drm_device *dev, drm_atomic_helper_swap_state(dev, state); dev_priv->wm.config = intel_state->wm_config; + dev_priv->wm.distrust_bios_wm = false; intel_shared_dpll_commit(state); if (intel_state->modeset) { diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index ca38f6c0e3c8..87fae2e93c40 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -4026,6 +4026,14 @@ void skl_wm_get_hw_state(struct drm_device *dev) list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) skl_pipe_wm_get_hw_state(crtc); + if (dev_priv->active_crtcs) { + /* Fully recompute DDB on first atomic commit */ + dev_priv->wm.distrust_bios_wm = true; + } else { + /* Easy/common case; just sanitize DDB now if everything off */ + memset(ddb, 0, sizeof(*ddb)); + } + /* Calculate plane data rates */ for_each_intel_crtc(dev, intel_crtc) { struct intel_crtc_state *cstate = intel_crtc->config;