linux-kernel - [PATCH] Revert "drm/nouveau/pmu/gm200-: avoid touching PMU outside of DEVINIT/PREOS/ACR"

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Message-Id: <20220205152729.2609837-1-kherbst@redhat.com>
Date:   Sat,  5 Feb 2022 16:27:28 +0100
From:   Karol Herbst <kherbst@...hat.com>
To:     linux-kernel@...r.kernel.org
Cc:     Karol Herbst <kherbst@...hat.com>, Ben Skeggs <bskeggs@...hat.com>,
        Lyude Paul <lyude@...hat.com>, David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        dri-devel@...ts.freedesktop.org (open list:DRM DRIVER FOR NVIDIA
        GEFORCE/QUADRO GPUS),
        nouveau@...ts.freedesktop.org (open list:DRM DRIVER FOR NVIDIA
        GEFORCE/QUADRO GPUS)
Subject: [PATCH] Revert "drm/nouveau/pmu/gm200-: avoid touching PMU outside of DEVINIT/PREOS/ACR"

This reverts commit 1d2271d2fb85e54bfc9630a6c30ac0feb9ffb983.

This fix actually causes regressions, which I could verify on my systems
as well. So let's revert it and figure out a proper fix for the original
problem.

Cc: Ben Skeggs <bskeggs@...hat.com>
Bug: https://gitlab.freedesktop.org/drm/nouveau/-/issues/149
Signed-off-by: Karol Herbst <kherbst@...hat.com>
---
 .../gpu/drm/nouveau/nvkm/subdev/pmu/base.c    | 37 ++++++++-----------
 1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c
index 455e95a89259..24382875fb4f 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/pmu/base.c
@@ -94,13 +94,20 @@ nvkm_pmu_fini(struct nvkm_subdev *subdev, bool suspend)
 	return 0;
 }
 
-static void
+static int
 nvkm_pmu_reset(struct nvkm_pmu *pmu)
 {
 	struct nvkm_device *device = pmu->subdev.device;
 
 	if (!pmu->func->enabled(pmu))
-		return;
+		return 0;
+
+	/* Inhibit interrupts, and wait for idle. */
+	nvkm_wr32(device, 0x10a014, 0x0000ffff);
+	nvkm_msec(device, 2000,
+		if (!nvkm_rd32(device, 0x10a04c))
+			break;
+	);
 
 	/* Reset. */
 	if (pmu->func->reset)
@@ -111,37 +118,25 @@ nvkm_pmu_reset(struct nvkm_pmu *pmu)
 		if (!(nvkm_rd32(device, 0x10a10c) & 0x00000006))
 			break;
 	);
+
+	return 0;
 }
 
 static int
 nvkm_pmu_preinit(struct nvkm_subdev *subdev)
 {
 	struct nvkm_pmu *pmu = nvkm_pmu(subdev);
-	nvkm_pmu_reset(pmu);
-	return 0;
+	return nvkm_pmu_reset(pmu);
 }
 
 static int
 nvkm_pmu_init(struct nvkm_subdev *subdev)
 {
 	struct nvkm_pmu *pmu = nvkm_pmu(subdev);
-	struct nvkm_device *device = pmu->subdev.device;
-
-	if (!pmu->func->init)
-		return 0;
-
-	if (pmu->func->enabled(pmu)) {
-		/* Inhibit interrupts, and wait for idle. */
-		nvkm_wr32(device, 0x10a014, 0x0000ffff);
-		nvkm_msec(device, 2000,
-			if (!nvkm_rd32(device, 0x10a04c))
-				break;
-		);
-
-		nvkm_pmu_reset(pmu);
-	}
-
-	return pmu->func->init(pmu);
+	int ret = nvkm_pmu_reset(pmu);
+	if (ret == 0 && pmu->func->init)
+		ret = pmu->func->init(pmu);
+	return ret;
 }
 
 static void *
-- 
2.34.1