[PATCH 01/11] drm/nouveau: tegra: Avoid pulsing reset twice

[Thierry Reding]

From: Thierry Reding <treding at nvidia.com>

When the GPU powergate is controlled by a generic power domain provider,
the reset will automatically be asserted and deasserted as part of the
power-ungating procedure.

On some Jetson TX2 boards, doing an additional assert and deassert of
the GPU outside of the power-ungate procedure can cause the GPU to go
into a bad state where the memory interface can no longer access system
memory.

Signed-off-by: Thierry Reding <treding at nvidia.com>
---
 drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
index 0e372a190d3f..747a775121cf 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
@@ -52,18 +52,18 @@ nvkm_device_tegra_power_up(struct nvkm_device_tegra *tdev)
 	clk_set_rate(tdev->clk_pwr, 204000000);
 	udelay(10);
 
-	reset_control_assert(tdev->rst);
-	udelay(10);
-
 	if (!tdev->pdev->dev.pm_domain) {
+		reset_control_assert(tdev->rst);
+		udelay(10);
+
 		ret = tegra_powergate_remove_clamping(TEGRA_POWERGATE_3D);
 		if (ret)
 			goto err_clamp;
 		udelay(10);
-	}
 
-	reset_control_deassert(tdev->rst);
-	udelay(10);
+		reset_control_deassert(tdev->rst);
+		udelay(10);
+	}
 
 	return 0;
 
-- 
2.23.0