| Message ID | 1372177266-2665-4-git-send-email-ville.syrjala@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 25 Jun 2013 19:21:03 +0300 ville.syrjala@linux.intel.com wrote: > From: Ville Syrjälä <ville.syrjala@linux.intel.com> > > Don't do needless udelay() calls if the Punit already completed > the frequency change. > > Also double check things after the timeout to make sure the timeout > wasn't just caused by some scheduling delays. > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > --- > drivers/gpu/drm/i915/intel_pm.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > index 6dbcad7..6b98d45 100644 > --- a/drivers/gpu/drm/i915/intel_pm.c > +++ b/drivers/gpu/drm/i915/intel_pm.c > @@ -3078,14 +3078,20 @@ static void vlv_update_rps_cur_delay(struct drm_i915_private *dev_priv) > > WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock)); > > - do { > - pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); > + pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); > + > + while (pval & 1) { > if (time_after(jiffies, timeout)) { > - DRM_DEBUG_DRIVER("timed out waiting for Punit\n"); > + pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); > break; > } > + > udelay(10); > - } while (pval & 1); > + pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); > + } > + > + if (pval & 1) > + DRM_DEBUG_DRIVER("timed out waiting for Punit\n"); > > pval >>= 8; > Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
On Tue, Jun 25, 2013 at 07:21:03PM +0300, ville.syrjala@linux.intel.com wrote: > From: Ville Syrjälä <ville.syrjala@linux.intel.com> > > Don't do needless udelay() calls if the Punit already completed > the frequency change. > > Also double check things after the timeout to make sure the timeout > wasn't just caused by some scheduling delays. > > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> > --- > drivers/gpu/drm/i915/intel_pm.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c > index 6dbcad7..6b98d45 100644 > --- a/drivers/gpu/drm/i915/intel_pm.c > +++ b/drivers/gpu/drm/i915/intel_pm.c > @@ -3078,14 +3078,20 @@ static void vlv_update_rps_cur_delay(struct drm_i915_private *dev_priv) > > WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock)); > > - do { > - pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); > + pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); > + > + while (pval & 1) { > if (time_after(jiffies, timeout)) { > - DRM_DEBUG_DRIVER("timed out waiting for Punit\n"); > + pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); > break; > } > + > udelay(10); > - } while (pval & 1); > + pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); > + } > + > + if (pval & 1) > + DRM_DEBUG_DRIVER("timed out waiting for Punit\n"); Since we notoriously get these suckers wrong and this check isn't really in the critical path any more (the punit should have complete the last change already) and furthermore in a work item: Can we just use one of our bog-standard wait_for macros here now? -Daniel
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index 6dbcad7..6b98d45 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -3078,14 +3078,20 @@ static void vlv_update_rps_cur_delay(struct drm_i915_private *dev_priv) WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock)); - do { - pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); + pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); + + while (pval & 1) { if (time_after(jiffies, timeout)) { - DRM_DEBUG_DRIVER("timed out waiting for Punit\n"); + pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); break; } + udelay(10); - } while (pval & 1); + pval = vlv_punit_read(dev_priv, PUNIT_REG_GPU_FREQ_STS); + } + + if (pval & 1) + DRM_DEBUG_DRIVER("timed out waiting for Punit\n"); pval >>= 8;