| Message ID | 1467110253-16046-4-git-send-email-imre.deak@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 28/06/16 11:37, Imre Deak wrote: > Since wait_for_atomic doesn't re-check the wait-for condition after > expiry of the timeout it can fail when called from non-atomic context > even if the condition is set correctly before the expiry. Fix this by > using the non-atomic wait_for instead. > > Fixes: 0351b93992aa ("drm/i915: Do not lie about atomic timeout granularity") > CC: Chris Wilson <chris@chris-wilson.co.uk> > CC: Tvrtko Ursulin <tvrtko.ursulin@intel.com> > Signed-off-by: Imre Deak <imre.deak@intel.com> > --- > drivers/gpu/drm/i915/intel_display.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index 0312472..d902a70 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -9534,8 +9534,8 @@ static void hsw_disable_lcpll(struct drm_i915_private *dev_priv, > val |= LCPLL_CD_SOURCE_FCLK; > I915_WRITE(LCPLL_CTL, val); > > - if (wait_for_atomic_us(I915_READ(LCPLL_CTL) & > - LCPLL_CD_SOURCE_FCLK_DONE, 1)) > + if (wait_for_us(I915_READ(LCPLL_CTL) & > + LCPLL_CD_SOURCE_FCLK_DONE, 1)) > DRM_ERROR("Switching to FCLK failed\n"); > > val = I915_READ(LCPLL_CTL); > @@ -9608,8 +9608,8 @@ static void hsw_restore_lcpll(struct drm_i915_private *dev_priv) > val &= ~LCPLL_CD_SOURCE_FCLK; > I915_WRITE(LCPLL_CTL, val); > > - if (wait_for_atomic_us((I915_READ(LCPLL_CTL) & > - LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1)) > + if (wait_for_us((I915_READ(LCPLL_CTL) & > + LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1)) > DRM_ERROR("Switching back to LCPLL failed\n"); > } > > This one is also on a mutex-taking path so looks correct to me. Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Since it just a 1us timeout, as I wrote in another reply I can follow up with a patch to implement those more efficiently. Does not make anything worse in the meantime unless operation times out which is not critical. Regards, Tvrtko
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 0312472..d902a70 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -9534,8 +9534,8 @@ static void hsw_disable_lcpll(struct drm_i915_private *dev_priv, val |= LCPLL_CD_SOURCE_FCLK; I915_WRITE(LCPLL_CTL, val); - if (wait_for_atomic_us(I915_READ(LCPLL_CTL) & - LCPLL_CD_SOURCE_FCLK_DONE, 1)) + if (wait_for_us(I915_READ(LCPLL_CTL) & + LCPLL_CD_SOURCE_FCLK_DONE, 1)) DRM_ERROR("Switching to FCLK failed\n"); val = I915_READ(LCPLL_CTL); @@ -9608,8 +9608,8 @@ static void hsw_restore_lcpll(struct drm_i915_private *dev_priv) val &= ~LCPLL_CD_SOURCE_FCLK; I915_WRITE(LCPLL_CTL, val); - if (wait_for_atomic_us((I915_READ(LCPLL_CTL) & - LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1)) + if (wait_for_us((I915_READ(LCPLL_CTL) & + LCPLL_CD_SOURCE_FCLK_DONE) == 0, 1)) DRM_ERROR("Switching back to LCPLL failed\n"); }
Since wait_for_atomic doesn't re-check the wait-for condition after expiry of the timeout it can fail when called from non-atomic context even if the condition is set correctly before the expiry. Fix this by using the non-atomic wait_for instead. Fixes: 0351b93992aa ("drm/i915: Do not lie about atomic timeout granularity") CC: Chris Wilson <chris@chris-wilson.co.uk> CC: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> --- drivers/gpu/drm/i915/intel_display.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)