From: Ville Syrjälä Date: Wed, 3 Jun 2015 12:45:11 +0000 (+0300) Subject: drm/i915: Don't enable IPS when pixel rate exceeds 95% X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=8cfb340774744438dea08a32072bea4a162dd132;p=linux-beck.git 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 Signed-off-by: Ville Syrjälä Signed-off-by: Mika Kahola Reviewed-by: Damien Lespiau Signed-off-by: Jani Nikula --- diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 445385dd062a..c3f01aa9b510 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -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, diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 2afb31a46275..5cb30044acf4 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -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); diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 5db429e92be5..d091fec1e101 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -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 =