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 Tested-by: Timo Aaltonen <tjaal...@ubuntu.com> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=83497 Signed-off-by: Ville Syrjälä <ville.syrj...@linux.intel.com> v4: Rebased to the latest Signed-off-by: Mika Kahola <mika.kah...@intel.com> --- drivers/gpu/drm/i915/intel_display.c | 30 ++++++++++++++++++++++++++++-- drivers/gpu/drm/i915/intel_drv.h | 2 +- drivers/gpu/drm/i915/intel_pm.c | 17 ++++++++--------- 3 files changed, 37 insertions(+), 12 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index dbc880e..fa7baf2 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -6072,12 +6072,38 @@ 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, diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 082be71..34ee6b9 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -1351,7 +1351,7 @@ 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); diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 79e4afd..b130520 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -1435,23 +1435,22 @@ 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) @@ -2067,7 +2066,7 @@ 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.enabled = true; -- 1.9.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
