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Commit 7d28dbae authored by Karol Herbst's avatar Karol Herbst Committed by Ben Skeggs
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drm/nouveau/pmu: be more strict about locking 



When we start communicating with the pmu a bit more, the current code is
a real issue. I encountered a dead lock here, while testing my dynamic
reclocking code

Signed-off-by: default avatarKarol Herbst <nouveau@karolherbst.de>
Signed-off-by: default avatarBen Skeggs <bskeggs@redhat.com>
parent c6007dc4

drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c

+5 −3
Original line number Diff line number Diff line
@@ -40,21 +40,23 @@ nvkm_pmu_send(struct nvkm_pmu *pmu, u32 reply[2], 
	struct nvkm_device *device = subdev->device;

	u32 addr;



	mutex_lock(&subdev->mutex);

	/* wait for a free slot in the fifo */

	addr  = nvkm_rd32(device, 0x10a4a0);

	if (nvkm_msec(device, 2000,

		u32 tmp = nvkm_rd32(device, 0x10a4b0);

		if (tmp != (addr ^ 8))

			break;

	) < 0)

	) < 0) {

		mutex_unlock(&subdev->mutex);

		return -EBUSY;

	}



	/* we currently only support a single process at a time waiting

	 * on a synchronous reply, take the PMU mutex and tell the

	 * receive handler what we're waiting for

	 */

	if (reply) {

		mutex_lock(&subdev->mutex);

		pmu->recv.message = message;

		pmu->recv.process = process;

	}
@@ -81,9 +83,9 @@ nvkm_pmu_send(struct nvkm_pmu *pmu, u32 reply[2], 
		wait_event(pmu->recv.wait, (pmu->recv.process == 0));

		reply[0] = pmu->recv.data[0];

		reply[1] = pmu->recv.data[1];

		mutex_unlock(&subdev->mutex);

	}



	mutex_unlock(&subdev->mutex);

	return 0;

}