[PATCH v2] nvme: put some AMD PCIE downstream NVME device to simple suspend/resume path

[Chaitanya Kulkarni]

> try do the NVME shutdown save and restore in the BIOS and still need PCIe
> power seting to resume from RTD3 for s2idle.

s/seting/setting/ ? idk.

> Signed-off-by: Prike Liang <Prike.Liang at amd.com>
> ---
> Changes in v2:
>  Fix the patch format and check chip root complex DID instead of PCIe RP
>   to avoid the storage device plugged in internal PCIe RP by USB adaptor.
> ---
>  drivers/nvme/host/pci.c | 19 +++++++++++++++++++
>  1 file changed, 19 insertions(+)
>
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 6bad4d4..1952da1 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -42,6 +42,9 @@
>  #define NVME_MAX_KB_SZ	4096
>  #define NVME_MAX_SEGS	127
>  
> +#define AMD_PCIE_ID_CZN 0x1630
> +#define AMD_PCIE_ID_RN AMD_PCIE_ID_CZN
> +
>  static int use_threaded_interrupts;
>  module_param(use_threaded_interrupts, int, 0);
>  
> @@ -70,6 +73,12 @@ static unsigned int io_queue_depth = 1024;
>  module_param_cb(io_queue_depth, &io_queue_depth_ops, &io_queue_depth, 0644);
>  MODULE_PARM_DESC(io_queue_depth, "set io queue depth, should >= 2");
>  
> +static const struct pci_device_id pcie_ids[] = {
> +	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, AMD_PCIE_ID_RN) },
> +	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, AMD_PCIE_ID_CZN) },
> +	{ }
> +};
> +

why new global pci_device_id array is needed ?

>  static int io_queue_count_set(const char *val, const struct kernel_param *kp)
>  {
>  	unsigned int n;
> @@ -2832,6 +2841,7 @@ static bool nvme_acpi_storage_d3(struct pci_dev *dev)
>  {
>  	struct acpi_device *adev;
>  	struct pci_dev *root;
> +	struct pci_dev *rdev;
>  	acpi_handle handle;
>  	acpi_status status;
>  	u8 val;
> @@ -2845,6 +2855,15 @@ static bool nvme_acpi_storage_d3(struct pci_dev *dev)
>  	if (!root)
>  		return false;
>  
> +	rdev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
> +	if (rdev && pci_match_id(pcie_ids, rdev)) {
> +	/* Detect NVME device which pluged in the Renoir PCIE root port
> +	 * then force use quick suspend/resume path for handling the NVME
> +	 * timeout during s2idle resume.
> +	 */

The comment should something like this :-

              if (rdev && pci_match_id(pcie_ids, rdev)) {

		/* 
		 * Detect NVMe device which pluged in the Renoir PCIe root port
		 * then force use quick suspend/resume path for handling the NVMe
		 * timeout during s2idle resume.
		 */return NVME_QUIRK_SIMPLE_SUSPEND;

          }
> +		return NVME_QUIRK_SIMPLE_SUSPEND;
> +	}
> +
>  	adev = ACPI_COMPANION(&root->dev);
>  	if (!adev)
>  		return false;