drm/i915: vlv: factor out vlv_force_gfx_clock and check for pending force-off
This will be needed by the VLV runtime PM helpers too, so factor it out.
Also add a safety check for the case where the previous force-off is
still pending, since I'm not sure if Punit can handle a new setting
while the previous one hasn't settled yet.
v2:
- unchanged
v3:
- add a note to the commit message about the safety check (Ville)
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index e3c9c44..9f3e977 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -933,6 +933,43 @@
hsw_disable_pc8(dev_priv);
}
+int vlv_force_gfx_clock(struct drm_i915_private *dev_priv, bool force_on)
+{
+ u32 val;
+ int err;
+
+ val = I915_READ(VLV_GTLC_SURVIVABILITY_REG);
+ WARN_ON(!!(val & VLV_GFX_CLK_FORCE_ON_BIT) == force_on);
+
+#define COND (I915_READ(VLV_GTLC_SURVIVABILITY_REG) & VLV_GFX_CLK_STATUS_BIT)
+ /* Wait for a previous force-off to settle */
+ if (force_on) {
+ err = wait_for(!COND, 5);
+ 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;
+ if (force_on)
+ val |= VLV_GFX_CLK_FORCE_ON_BIT;
+ I915_WRITE(VLV_GTLC_SURVIVABILITY_REG, val);
+
+ if (!force_on)
+ return 0;
+
+ err = wait_for(COND, 5);
+ if (err)
+ DRM_ERROR("timeout waiting for GFX clock force-on (%08x)\n",
+ I915_READ(VLV_GTLC_SURVIVABILITY_REG));
+
+ return err;
+#undef COND
+}
+
static int intel_runtime_suspend(struct device *device)
{
struct pci_dev *pdev = to_pci_dev(device);