drm/i915: Don't enable IPS when pixel rate exceeds 95%

Bspec says we shouldn't enable IPS on BDW when the pipe pixel rate
exceeds 95% of the core display clock. Apparently this can cause
underruns.

There's no similar restriction listed for HSW, so leave that one alone
for now.

v2: Add pipe_config_supports_ips() (Chris)
v3: Compare against the max cdclk insted of the current cdclk
v4: Rebased to the latest
v5: Rebased to the latest
v6: Fix for patch style problems

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83497
Tested-by: Timo Aaltonen <tjaalton@ubuntu.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Mika Kahola <mika.kahola@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Ville Syrjälä 2015-06-03 15:45:11 +03:00 committed by Jani Nikula
parent 44913155f0
commit 8cfb340774
3 changed files with 37 additions and 12 deletions

View File

@ -6610,12 +6610,38 @@ retry:
return ret;
}
static bool pipe_config_supports_ips(struct drm_i915_private *dev_priv,
struct intel_crtc_state *pipe_config)
{
if (pipe_config->pipe_bpp > 24)
return false;
/* HSW can handle pixel rate up to cdclk? */
if (IS_HASWELL(dev_priv->dev))
return true;
/*
* FIXME if we compare against max we should then
* increase the cdclk frequency when the current
* value is too low. The other option is to compare
* against the cdclk frequency we're going have post
* modeset (ie. one we computed using other constraints).
* Need to measure whether using a lower cdclk w/o IPS
* is better or worse than a higher cdclk w/ IPS.
*/
return ilk_pipe_pixel_rate(pipe_config) <=
dev_priv->max_cdclk_freq * 95 / 100;
}
static void hsw_compute_ips_config(struct intel_crtc *crtc,
struct intel_crtc_state *pipe_config)
{
struct drm_device *dev = crtc->base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
pipe_config->ips_enabled = i915.enable_ips &&
hsw_crtc_supports_ips(crtc) &&
pipe_config->pipe_bpp <= 24;
hsw_crtc_supports_ips(crtc) &&
pipe_config_supports_ips(dev_priv, pipe_config);
}
static int intel_crtc_compute_config(struct intel_crtc *crtc,

View File

@ -1375,7 +1375,7 @@ void ilk_wm_get_hw_state(struct drm_device *dev);
void skl_wm_get_hw_state(struct drm_device *dev);
void skl_ddb_get_hw_state(struct drm_i915_private *dev_priv,
struct skl_ddb_allocation *ddb /* out */);
uint32_t ilk_pipe_pixel_rate(const struct intel_crtc_state *pipe_config);
/* intel_sdvo.c */
bool intel_sdvo_init(struct drm_device *dev, uint32_t sdvo_reg, bool is_sdvob);

View File

@ -1434,23 +1434,22 @@ static void i845_update_wm(struct drm_crtc *unused_crtc)
I915_WRITE(FW_BLC, fwater_lo);
}
static uint32_t ilk_pipe_pixel_rate(struct drm_device *dev,
struct drm_crtc *crtc)
uint32_t ilk_pipe_pixel_rate(const struct intel_crtc_state *pipe_config)
{
struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
uint32_t pixel_rate;
pixel_rate = intel_crtc->config->base.adjusted_mode.crtc_clock;
pixel_rate = pipe_config->base.adjusted_mode.crtc_clock;
/* We only use IF-ID interlacing. If we ever use PF-ID we'll need to
* adjust the pixel_rate here. */
if (intel_crtc->config->pch_pfit.enabled) {
if (pipe_config->pch_pfit.enabled) {
uint64_t pipe_w, pipe_h, pfit_w, pfit_h;
uint32_t pfit_size = intel_crtc->config->pch_pfit.size;
uint32_t pfit_size = pipe_config->pch_pfit.size;
pipe_w = pipe_config->pipe_src_w;
pipe_h = pipe_config->pipe_src_h;
pipe_w = intel_crtc->config->pipe_src_w;
pipe_h = intel_crtc->config->pipe_src_h;
pfit_w = (pfit_size >> 16) & 0xFFFF;
pfit_h = pfit_size & 0xFFFF;
if (pipe_w < pfit_w)
@ -2066,7 +2065,7 @@ static void ilk_compute_wm_parameters(struct drm_crtc *crtc,
p->active = true;
p->pipe_htotal = intel_crtc->config->base.adjusted_mode.crtc_htotal;
p->pixel_rate = ilk_pipe_pixel_rate(dev, crtc);
p->pixel_rate = ilk_pipe_pixel_rate(intel_crtc->config);
if (crtc->primary->state->fb)
p->pri.bytes_per_pixel =