Nouveau - Jun 2017 - [PATCH 2/3] drm/nouveau/tegra: Don't leave GPU in reset

On Tegra186, powergating is handled by the BPMP power domain provider
and the "legacy" powergating API is not available. Therefore skip
these calls if we are attached to a power domain.

Signed-off-by: Mikko Perttunen <mperttunen at nvidia.com>
---
 drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
index 6474bd2a6d07..3d42cdbbe9c0 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
@@ -51,10 +51,12 @@ nvkm_device_tegra_power_up(struct nvkm_device_tegra *tdev)
 	reset_control_assert(tdev->rst);
 	udelay(10);
 
-	ret = tegra_powergate_remove_clamping(TEGRA_POWERGATE_3D);
-	if (ret)
-		goto err_clamp;
-	udelay(10);
+	if (!tdev->pdev->dev.pm_domain) {
+		ret = tegra_powergate_remove_clamping(TEGRA_POWERGATE_3D);
+		if (ret)
+			goto err_clamp;
+		udelay(10);
+	}
 
 	reset_control_deassert(tdev->rst);
 	udelay(10);
-- 
2.13.0

On Tegra186 systems with certain firmware revisions, leaving the GPU in
reset can cause a hang. To prevent this, don't leave the GPU in reset.

Signed-off-by: Mikko Perttunen <mperttunen at nvidia.com>
---
 drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
index 3d42cdbbe9c0..189ed80e21ff 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
@@ -82,9 +82,6 @@ nvkm_device_tegra_power_down(struct nvkm_device_tegra *tdev)
 {
 	int ret;
 
-	reset_control_assert(tdev->rst);
-	udelay(10);
-
 	clk_disable_unprepare(tdev->clk_pwr);
 	if (tdev->clk_ref)
 		clk_disable_unprepare(tdev->clk_ref);
-- 
2.13.0

As with vga_init, this function doesn't make sense on non-PCI devices,
and the Thunderbolt check in it dereferences a NULL pointer in that
case. Add some code to skip this function when the device is not a PCI
device.

Signed-off-by: Mikko Perttunen <mperttunen at nvidia.com>
---
 drivers/gpu/drm/nouveau/nouveau_vga.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/nouveau_vga.c
b/drivers/gpu/drm/nouveau/nouveau_vga.c
index a4aacbc0cec8..b19dd4dc7099 100644
--- a/drivers/gpu/drm/nouveau/nouveau_vga.c
+++ b/drivers/gpu/drm/nouveau/nouveau_vga.c
@@ -115,6 +115,10 @@ nouveau_vga_fini(struct nouveau_drm *drm)
 	struct drm_device *dev = drm->dev;
 	bool runtime = false;
 
+	/* only relevant for PCI devices */
+	if (!dev->pdev)
+		return;
+
 	vga_client_register(dev->pdev, NULL, NULL, NULL);
 
 	if (pci_is_thunderbolt_attached(dev->pdev))
-- 
2.13.0

On 06/09/2017 10:25 PM, Mikko Perttunen wrote:
> On Tegra186, powergating is handled by the BPMP power domain provider
> and the "legacy" powergating API is not available. Therefore skip
> these calls if we are attached to a power domain.
Thanks Mikko,

Taken all 3 patches into my tree.

Ben.
> 
> Signed-off-by: Mikko Perttunen <mperttunen at nvidia.com>
> ---
>  drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
> index 6474bd2a6d07..3d42cdbbe9c0 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
> @@ -51,10 +51,12 @@ nvkm_device_tegra_power_up(struct nvkm_device_tegra
*tdev)
>  	reset_control_assert(tdev->rst);
>  	udelay(10);
>  
> -	ret = tegra_powergate_remove_clamping(TEGRA_POWERGATE_3D);
> -	if (ret)
> -		goto err_clamp;
> -	udelay(10);
> +	if (!tdev->pdev->dev.pm_domain) {
> +		ret = tegra_powergate_remove_clamping(TEGRA_POWERGATE_3D);
> +		if (ret)
> +			goto err_clamp;
> +		udelay(10);
> +	}
>  
>  	reset_control_deassert(tdev->rst);
>  	udelay(10);
> 
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On 13.06.2017 01:52, Ben Skeggs wrote:
> On 06/09/2017 10:25 PM, Mikko Perttunen wrote:
>> On Tegra186, powergating is handled by the BPMP power domain provider
>> and the "legacy" powergating API is not available. Therefore
skip
>> these calls if we are attached to a power domain.
> Thanks Mikko,
>
> Taken all 3 patches into my tree.
Thanks!
>
> Ben.
>
>>
>> Signed-off-by: Mikko Perttunen <mperttunen at nvidia.com>
>> ---
>>  drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c | 10 ++++++----
>>  1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
>> index 6474bd2a6d07..3d42cdbbe9c0 100644
>> --- a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
>> +++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
>> @@ -51,10 +51,12 @@ nvkm_device_tegra_power_up(struct nvkm_device_tegra
*tdev)
>>  	reset_control_assert(tdev->rst);
>>  	udelay(10);
>>
>> -	ret = tegra_powergate_remove_clamping(TEGRA_POWERGATE_3D);
>> -	if (ret)
>> -		goto err_clamp;
>> -	udelay(10);
>> +	if (!tdev->pdev->dev.pm_domain) {
>> +		ret = tegra_powergate_remove_clamping(TEGRA_POWERGATE_3D);
>> +		if (ret)
>> +			goto err_clamp;
>> +		udelay(10);
>> +	}
>>
>>  	reset_control_deassert(tdev->rst);
>>  	udelay(10);
>>
>