drm/i915: Sanitize watermarks after hardware state readout (v4)

Although we can do a good job of reading out hardware state, the
graphics firmware may have programmed the watermarks in a creative way
that doesn't match how i915 would have chosen to program them.  We
shouldn't trust the firmware's watermark programming, but should rather
re-calculate how we think WM's should be programmed and then shove those
values into the hardware.

We can do this pretty easily by creating a dummy top-level state,
running it through the check process to calculate all the values, and
then just programming the watermarks for each CRTC.

v2:  Move watermark sanitization after our BIOS fb reconstruction; the
     watermark calculations that we do here need to look at pstate->fb,
     which isn't setup yet in intel_modeset_setup_hw_state(), even
     though we have an enabled & visible plane.

v3:
 - Don't move 'active = optimal' watermark assignment; we just undo
   that change in the next patch anyway.  (Ville)
 - Move atomic helper locking fix to separate patch.  (Maarten)

v4:
 - Grab connection_mutex before calling atomic helper to duplicate
   state.  The connector loop inside the helper will throw a WARN
   if we don't hold something to protect the connector list (and the
   helper itself doesn't try to lock the list).
 - Make failure to calculate watermarks for inherited state a WARN()
   since it probably indicates a serious problem in either our state
   readout code or our watermark code for this platform.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
This commit is contained in:
Matt Roper
2015-12-03 11:37:41 -08:00
committed by Maarten Lankhorst
parent 151268821e
commit d93c037246
3 changed files with 86 additions and 4 deletions

View File

@@ -3617,9 +3617,11 @@ static void skl_update_wm(struct drm_crtc *crtc)
dev_priv->wm.skl_hw = *results;
}
static void ilk_program_watermarks(struct drm_i915_private *dev_priv)
static void ilk_program_watermarks(struct intel_crtc_state *cstate)
{
struct drm_device *dev = dev_priv->dev;
struct drm_crtc *crtc = cstate->base.crtc;
struct drm_device *dev = crtc->dev;
struct drm_i915_private *dev_priv = to_i915(dev);
struct intel_pipe_wm lp_wm_1_2 = {}, lp_wm_5_6 = {}, *best_lp_wm;
struct ilk_wm_maximums max;
struct intel_wm_config *config = &dev_priv->wm.config;
@@ -3650,7 +3652,6 @@ static void ilk_program_watermarks(struct drm_i915_private *dev_priv)
static void ilk_update_wm(struct drm_crtc *crtc)
{
struct drm_i915_private *dev_priv = to_i915(crtc->dev);
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
struct intel_crtc_state *cstate = to_intel_crtc_state(crtc->state);
@@ -3670,7 +3671,7 @@ static void ilk_update_wm(struct drm_crtc *crtc)
intel_crtc->wm.active.ilk = cstate->wm.optimal.ilk;
ilk_program_watermarks(dev_priv);
ilk_program_watermarks(cstate);
}
static void skl_pipe_wm_active_state(uint32_t val,
@@ -7000,6 +7001,7 @@ void intel_init_pm(struct drm_device *dev)
dev_priv->wm.spr_latency[0] && dev_priv->wm.cur_latency[0])) {
dev_priv->display.update_wm = ilk_update_wm;
dev_priv->display.compute_pipe_wm = ilk_compute_pipe_wm;
dev_priv->display.program_watermarks = ilk_program_watermarks;
} else {
DRM_DEBUG_KMS("Failed to read display plane latency. "
"Disable CxSR\n");