On 11/29/2023 02:51, Ma Jun wrote:
Some platforms can't resume from d3cold state, So add a
new module parameter to disable d3cold state for debugging
purpose or workaround.
Signed-off-by: Ma Jun <Jun.Ma2@xxxxxxx>
---
This patch is essentially an 'amdgpu knob' for d3cold on the root port.
At least for debugging purposes we also have a sysfs file
'd3cold_allowed' that will enact the same behavior.
I do have a patch that I proposed to PCI core that stops d3cold_allowed
from working in favor of requesting pcie_port_pm=off to be used instead
for debugging purposes.
However that's a 'relatively big' debugging knob however as it will
apply to all PCIe root ports.
Considering above I'm in favor of this being available as a localized
debugging path for just the root port the dGPU is connected to.
Some comments below though:
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 +
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 7 +++++++
drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 8 ++++++++
3 files changed, 16 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index a9f54df9d33e..db9f60790267 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -166,6 +166,7 @@ extern char amdgpu_lockup_timeout[AMDGPU_MAX_TIMEOUT_PARAM_LENGTH];
extern int amdgpu_dpm;
extern int amdgpu_fw_load_type;
extern int amdgpu_aspm;
+extern int amdgpu_d3cold;
extern int amdgpu_runtime_pm;
extern uint amdgpu_ip_block_mask;
extern int amdgpu_bapm;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 22b6a910b7f2..90501c44e7d0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -264,6 +264,13 @@ bool amdgpu_device_supports_px(struct drm_device *dev)
bool amdgpu_device_supports_boco(struct drm_device *dev)
{
struct amdgpu_device *adev = drm_to_adev(dev);
+ struct pci_dev *parent;
+
+ if (!amdgpu_d3cold) {
+ parent = pcie_find_root_port(adev->pdev);
+ pci_d3cold_disable(parent);
+ return false;
+ }
if (adev->has_pr3 ||
((adev->flags & AMD_IS_PX) && amdgpu_is_atpx_hybrid()))
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 5f14f04cb553..c9fbb8bd4169 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -145,6 +145,7 @@ char amdgpu_lockup_timeout[AMDGPU_MAX_TIMEOUT_PARAM_LENGTH];
int amdgpu_dpm = -1;
int amdgpu_fw_load_type = -1;
int amdgpu_aspm = -1;
+int amdgpu_d3cold = -1;
If this was chained to a larger workaround (such as automatically
applying to a DMI quirk) it would make sense as int and with using
-1 for auto. However there is a pretty dramatic downside for using this
knob that it can break s2idle.
In my testing I've found that the following happens on an A+A design
after s2idle with this parameter in use.
[ 70.572270] pcieport 0000:01:00.0: Unable to change power state from
D3cold to D0, device inaccessible
[ 70.572481] pcieport 0000:02:00.0: Unable to change power state from
D3cold to D0, device inaccessible
[ 72.855769] amdgpu 0000:03:00.0: not ready 1023ms after resume; waiting
[ 73.943545] amdgpu 0000:03:00.0: not ready 2047ms after resume; waiting
[ 76.055602] amdgpu 0000:03:00.0: not ready 4095ms after resume; waiting
[ 80.279550] amdgpu 0000:03:00.0: not ready 8191ms after resume; waiting
[ 88.983562] amdgpu 0000:03:00.0: not ready 16383ms after resume; waiting
[ 105.879581] amdgpu 0000:03:00.0: not ready 32767ms after resume; waiting
[ 142.743646] amdgpu 0000:03:00.0: not ready 65535ms after resume;
giving up
[ 142.743793] amdgpu 0000:03:00.0: Unable to change power state from
D3cold to D0, device inaccessible
[ 142.804011] snd_hda_intel 0000:03:00.1: Unable to change power state
from D3cold to D0, device inaccessible
So I don't see us ever automatically using this and it should be
debugging only. IOW this doesn't need to be integer; it can be boolean.
int amdgpu_runtime_pm = -1;
uint amdgpu_ip_block_mask = 0xffffffff;
int amdgpu_bapm = -1;
@@ -359,6 +360,13 @@ module_param_named(fw_load_type, amdgpu_fw_load_type, int, 0444);
MODULE_PARM_DESC(aspm, "ASPM support (1 = enable, 0 = disable, -1 = auto)");
module_param_named(aspm, amdgpu_aspm, int, 0444);
+/**
+ * DOC: d3cold (int)
If you flip it to boolean as I suggested this should probably either
rename to disable_d3cold or you should default to TRUE.
+ * To disable d3cold (1 = enable, 0 = disable). The default is -1 (auto, enabled).
+ */
+MODULE_PARM_DESC(d3cold, "d3cold support (1 = enable, 0 = disable, -1 = auto)");
+module_param_named(d3cold, amdgpu_d3cold, int, 0444);
+
/**
* DOC: runpm (int)
* Override for runtime power management control for dGPUs. The amdgpu driver can dynamically power down
