diff options
| author | Abhishek Sahu <abhsahu@nvidia.com> | 2019-06-06 14:52:25 +0530 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2019-06-13 15:53:40 -0500 |
| commit | 6d2e369f0d4c3e6125c886847c04106b03d2609e (patch) | |
| tree | ba516d273c83728c59130372ad7c93e386f3054a /drivers/pci/quirks.c | |
| parent | a17beb1a0882a544523dcb5d0da4801272dfd43a (diff) | |
| download | linux-6d2e369f0d4c3e6125c886847c04106b03d2609e.tar.gz | |
PCI: Add NVIDIA GPU multi-function power dependencies
The NVIDIA Turing GPU is a multi-function PCI device with the following
functions:
- Function 0: VGA display controller
- Function 1: Audio controller
- Function 2: USB xHCI Host controller
- Function 3: USB Type-C UCSI controller
Function 0 is tightly coupled with other functions in the hardware. When
function 0 is in D3, it gates power for hardware blocks used by other
functions, which means those functions only work when function 0 is in D0.
If any of these functions (1/2/3) are in D0, then function 0 should also be
in D0.
Commit 07f4f97d7b4b ("vga_switcheroo: Use device link for HDA controller")
already creates a device link to show the dependency of function 1 on
function 0 of this GPU. Create additional device links to express the
dependencies of functions 2 and 3 on function 0. This means function 0
will be in D0 if any other function is in D0.
[bhelgaas: I think the PCI spec expectation is that functions can be
power-managed independently, so I don't think this device is technically
compliant. For example, the PCIe r5.0 spec, sec 1.4, says "the PCI/PCIe
hardware/software model includes architectural constructs necessary to
discover, configure, and use a Function, without needing Function-specific
knowledge" and sec 5.1 says "D states are associated with a particular
Function" and "PM provides ... a mechanism to identify power management
capabilities of a given Function [and] the ability to transition a Function
into a certain power management state."]
Link: https://lore.kernel.org/lkml/20190606092225.17960-3-abhsahu@nvidia.com
Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci/quirks.c')
| -rw-r--r-- | drivers/pci/quirks.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index d9c162df9d529..c66c0ca446c48 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -4986,6 +4986,32 @@ DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID, PCI_CLASS_MULTIMEDIA_HD_AUDIO, 8, quirk_gpu_hda); /* + * Create device link for NVIDIA GPU with integrated USB xHCI Host + * controller to VGA. + */ +static void quirk_gpu_usb(struct pci_dev *usb) +{ + pci_create_device_link(usb, 2, 0, PCI_BASE_CLASS_DISPLAY, 16); +} +DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID, + PCI_CLASS_SERIAL_USB, 8, quirk_gpu_usb); + +/* + * Create device link for NVIDIA GPU with integrated Type-C UCSI controller + * to VGA. Currently there is no class code defined for UCSI device over PCI + * so using UNKNOWN class for now and it will be updated when UCSI + * over PCI gets a class code. + */ +#define PCI_CLASS_SERIAL_UNKNOWN 0x0c80 +static void quirk_gpu_usb_typec_ucsi(struct pci_dev *ucsi) +{ + pci_create_device_link(ucsi, 3, 0, PCI_BASE_CLASS_DISPLAY, 16); +} +DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID, + PCI_CLASS_SERIAL_UNKNOWN, 8, + quirk_gpu_usb_typec_ucsi); + +/* * Some IDT switches incorrectly flag an ACS Source Validation error on * completions for config read requests even though PCIe r4.0, sec * 6.12.1.1, says that completions are never affected by ACS Source |