drm/i915/lpt: Avoid early timeout during FDI PHY reset

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>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
CC: drm-intel-fixes@lists.freedesktop.org
Link: http://patchwork.freedesktop.org/patch/msgid/1467110253-16046-3-git-send-email-imre.deak@intel.com

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index c3b5dc8f5e80c64e473de2f2978e1dd4e4cce04d..0312472711cc6596f40aa8c7e21738ef6d289b3f 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8537,16 +8537,16 @@ static void lpt_reset_fdi_mphy(struct drm_i915_private *dev_priv)
        tmp |= FDI_MPHY_IOSFSB_RESET_CTL;
        I915_WRITE(SOUTH_CHICKEN2, tmp);
 
-       if (wait_for_atomic_us(I915_READ(SOUTH_CHICKEN2) &
-                              FDI_MPHY_IOSFSB_RESET_STATUS, 100))
+       if (wait_for_us(I915_READ(SOUTH_CHICKEN2) &
+                       FDI_MPHY_IOSFSB_RESET_STATUS, 100))
                DRM_ERROR("FDI mPHY reset assert timeout\n");
 
        tmp = I915_READ(SOUTH_CHICKEN2);
        tmp &= ~FDI_MPHY_IOSFSB_RESET_CTL;
        I915_WRITE(SOUTH_CHICKEN2, tmp);
 
-       if (wait_for_atomic_us((I915_READ(SOUTH_CHICKEN2) &
-                               FDI_MPHY_IOSFSB_RESET_STATUS) == 0, 100))
+       if (wait_for_us((I915_READ(SOUTH_CHICKEN2) &
+                        FDI_MPHY_IOSFSB_RESET_STATUS) == 0, 100))
                DRM_ERROR("FDI mPHY reset de-assert timeout\n");
 }