For LSPCON initialization during system resume we need AUX functionality, but we call the corresponding encoder reset hook with all interrupts disabled. Without interrupts we'll do a poll-wait for AUX transfer completions, which adds a significant delay if the transfers timeout/need to be retried for some reason. Fix this by enabling interrupts before calling the reset hooks. Note that while this will enable AUX interrupts it will keep HPD interrupts disabled, in a similar way to the init time output setup code. This issue existed since LSPCON support was added. v2: - Rebased on drm-tip. Cc: Shashank Sharma <shashank.sharma@xxxxxxxxx> Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Tested-by: David Weinehall <david.weinehall@xxxxxxxxxxxxxxx> Link: http://patchwork.freedesktop.org/patch/msgid/1480448429-27739-1-git-send-email-imre.deak@xxxxxxxxx (cherry picked from commit 908764f6d0bd1ba496cb8da33b9b98297ed27351) (corrected stable tag) Cc: <stable@xxxxxxxxxxxxxxx> # v4.10 Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> --- drivers/gpu/drm/i915/i915_drv.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index 728ca3e..f02da12 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -1573,18 +1573,21 @@ static int i915_drm_resume(struct drm_device *dev) intel_opregion_setup(dev_priv); intel_init_pch_refclk(dev); - drm_mode_config_reset(dev); /* * Interrupts have to be enabled before any batches are run. If not the * GPU will hang. i915_gem_init_hw() will initiate batches to * update/restore the context. * + * drm_mode_config_reset() needs AUX interrupts. + * * Modeset enabling in intel_modeset_init_hw() also needs working * interrupts. */ intel_runtime_pm_enable_interrupts(dev_priv); + drm_mode_config_reset(dev); + mutex_lock(&dev->struct_mutex); if (i915_gem_init_hw(dev)) { DRM_ERROR("failed to re-initialize GPU, declaring wedged!\n"); -- 2.5.0