msm: kgsl: use kgsl_mmu_device_setstate() if the GPU is already idle
Use the default setstate function, which directly reprograms the IOMMU,
to change IOMMU pagetables or flush the TLB if the GPU is already idle.
This condition often occurs when the GPU is being powered down. In this
case it is desirable to avoid the overhead of issuing commands, waiting
for idle and firing events that results from using the GPU
command stream to reprogram the IOMMU.
Change-Id: I633002ac49c8fe58df3f1f6a1fd1ddf705fc1733
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
diff --git a/drivers/gpu/msm/adreno.c b/drivers/gpu/msm/adreno.c
index de1048e..b9f00b5 100644
--- a/drivers/gpu/msm/adreno.c
+++ b/drivers/gpu/msm/adreno.c
@@ -310,8 +310,14 @@
struct kgsl_context *context;
struct adreno_context *adreno_ctx = NULL;
- if (!adreno_dev->drawctxt_active)
+ /*
+ * If we're idle and we don't need to use the GPU to save context
+ * state, use the CPU instead of the GPU to reprogram the
+ * iommu for simplicity's sake.
+ */
+ if (!adreno_dev->drawctxt_active || device->ftbl->isidle(device))
return kgsl_mmu_device_setstate(&device->mmu, flags);
+
num_iommu_units = kgsl_mmu_get_num_iommu_units(&device->mmu);
context = idr_find(&device->context_idr, context_id);