drm/i915, intel_ips: When i915 loads after IPS, make IPS relink to i915.
The IPS driver is designed to be able to run detached from i915 and
just not enable GPU turbo in that case, in order to avoid module
dependencies between the two drivers. This means that we don't know
what the load order between the two is going to be, and we had
previously only supported IPS after (optionally) i915, but not i915
after IPS. If the wrong order was chosen, you'd get no GPU turbo, and
something like half the possible graphics performance.
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index e680081..cb900dc 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -34,6 +34,7 @@
#include "i915_drm.h"
#include "i915_drv.h"
#include "i915_trace.h"
+#include "../../../platform/x86/intel_ips.h"
#include <linux/pci.h>
#include <linux/vgaarb.h>
#include <linux/acpi.h>
@@ -1871,6 +1872,26 @@
EXPORT_SYMBOL_GPL(i915_gpu_turbo_disable);
/**
+ * Tells the intel_ips driver that the i915 driver is now loaded, if
+ * IPS got loaded first.
+ *
+ * This awkward dance is so that neither module has to depend on the
+ * other in order for IPS to do the appropriate communication of
+ * GPU turbo limits to i915.
+ */
+static void
+ips_ping_for_i915_load(void)
+{
+ void (*link)(void);
+
+ link = symbol_get(ips_link_to_i915_driver);
+ if (link) {
+ link();
+ symbol_put(ips_link_to_i915_driver);
+ }
+}
+
+/**
* i915_driver_load - setup chip and create an initial config
* @dev: DRM device
* @flags: startup flags
@@ -2075,6 +2096,8 @@
dev_priv->mchdev_lock = &mchdev_lock;
spin_unlock(&mchdev_lock);
+ ips_ping_for_i915_load();
+
return 0;
out_workqueue_free: