[PATCH 3.19 028/101] drm/i915/vlv: remove wait for previous GFX clk disable request

Greg Kroah-Hartman
2015-04-17T14:08:30Z

From: Jesse Barnes <jbarnes@virtuousgeek.org>

commit 5df0582bf036bb5f9a8ad8db5884fe13a55347d1 upstream.

Looks like it was introduced in:

commit 650ad970a39f8b6164fe8613edc150f585315289
Author: Imre Deak <imre.deak@intel.com>
Date: Fri Apr 18 16:35:02 2014 +0300

drm/i915: vlv: factor out vlv_force_gfx_clock and check for pending force-of

but I'm not sure why. It has caused problems for us in the past (see
85250ddff7a6 "drm/i915/chv: Remove Wait for a previous gfx force-off"
and 8d4eee9cd7a1 "drm/i915: vlv: increase timeout when forcing on the
GFX clock") and doesn't seem to be required, so let's just drop it.

References: https://bugs.freedesktop.org/show_bug.cgi?id=89611
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: Darren Hart <dvhart@linux.intel.com>
Reviewed-by: Deepak S <deepak.s@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/i915/i915_drv.c | 14 --------------
1 file changed, 14 deletions(-)

--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1197,21 +1197,7 @@ int vlv_force_gfx_clock(struct drm_i915_
u32 val;
int err;

- val = I915_READ(VLV_GTLC_SURVIVABILITY_REG);
-
#define COND (I915_READ(VLV_GTLC_SURVIVABILITY_REG) & VLV_GFX_CLK_STATUS_BIT)
- /* Wait for a previous force-off to settle */
- if (force_on && !IS_CHERRYVIEW(dev_priv->dev)) {
- /* WARN_ON only for the Valleyview */
- WARN_ON(!!(val & VLV_GFX_CLK_FORCE_ON_BIT) == force_on);
-
- err = wait_for(!COND, 20);
- if (err) {
- DRM_ERROR("timeout waiting for GFX clock force-off (%08x)\n",
- I915_READ(VLV_GTLC_SURVIVABILITY_REG));
- return err;
- }
- }

val = I915_READ(VLV_GTLC_SURVIVABILITY_REG);
val &= ~VLV_GFX_CLK_FORCE_ON_BIT;