On 20.4.2023 20.21, Weitao Wang wrote:
Add U1/U2 feature support of xHCI for zhaoxin.
Signed-off-by: Weitao Wang <WeitaoWang-oc@xxxxxxxxxxx>
---
drivers/usb/host/xhci-pci.c | 5 +++++
drivers/usb/host/xhci.c | 27 +++++++++++++++++++++++++--
2 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 6db07ca419c3..a235effe8e5c 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -334,6 +334,11 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
pdev->device == PCI_DEVICE_ID_AMD_PROMONTORYA_4))
xhci->quirks |= XHCI_NO_SOFT_RETRY;
+ if (pdev->vendor == PCI_VENDOR_ID_ZHAOXIN) {
+ xhci->quirks |= XHCI_LPM_SUPPORT;
+ xhci->quirks |= XHCI_ZHAOXIN_HOST;
+ }
+
/* xHC spec requires PCI devices to support D3hot and D3cold */
if (xhci->hci_version >= 0x120)
xhci->quirks |= XHCI_DEFAULT_PM_RUNTIME_ALLOW;
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 6307bae9cddf..730c0f68518d 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4802,7 +4802,7 @@ static u16 xhci_calculate_u1_timeout(struct xhci_hcd *xhci,
}
}
- if (xhci->quirks & XHCI_INTEL_HOST)
+ if (xhci->quirks & (XHCI_INTEL_HOST | XHCI_ZHAOXIN_HOST))
timeout_ns = xhci_calculate_intel_u1_timeout(udev, desc);
Looks odd to tie Zhaoxin vendor to Intel specific values but ok,
if they diverge in the future we anyway need to modify this.
else
timeout_ns = udev->u1_params.sel;
@@ -4866,7 +4866,7 @@ static u16 xhci_calculate_u2_timeout(struct xhci_hcd *xhci,
}
}
- if (xhci->quirks & XHCI_INTEL_HOST)
+ if (xhci->quirks & (XHCI_INTEL_HOST | XHCI_ZHAOXIN_HOST))
timeout_ns = xhci_calculate_intel_u2_timeout(udev, desc);
same.
else
timeout_ns = udev->u2_params.sel;
@@ -4938,6 +4938,27 @@ static int xhci_update_timeout_for_interface(struct xhci_hcd *xhci,
return 0;
}
+static int xhci_check_zhaoxin_tier_policy(struct usb_device *udev,
+ enum usb3_link_state state)
+{
+ struct usb_device *parent;
+ unsigned int num_hubs;
+
+ /* Don't enable U1/U2 if the device is on an external hub. */
+ for (parent = udev->parent, num_hubs = 0; parent->parent;
+ parent = parent->parent)
+ num_hubs++;
+
+ if (num_hubs < 1)
+ return 0;
+
+ dev_dbg(&udev->dev, "Disabling U1/U2 link state for device"
+ " below external hub.\n");
+ dev_dbg(&udev->dev, "Plug device into root hub "
+ "to decrease power consumption.\n");
+ return -E2BIG;
+}
+
I don't think we should add more vendor specific functions, this is almost
an exact copy of xhci_check_intel_tier_policy().
How about getting rid of both of those and use something like this instead (untested):
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 2b280beb0011..e9a25e4d99cf 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4926,10 +4926,24 @@ static int xhci_check_tier_policy(struct xhci_hcd *xhci,
struct usb_device *udev,
enum usb3_link_state state)
{
- if (xhci->quirks & XHCI_INTEL_HOST)
- return xhci_check_intel_tier_policy(udev, state);
- else
- return 0;
+ struct usb_device *parent = udev->parent;
+ int tier = 1; /* roothub is tier1 */
+
+ while (parent) {
+ parent = parent->parent;
+ tier++;
+ }
+
+ if (xhci->quirks & XHCI_INTEL_HOST && tier > 3)
+ goto fail;
+ if (xhci->quirks & XHCI_ZHAOXIN_HOST && tier > 2)
+ goto fail;
+
+ return 0;
+fail:
+ dev_dbg(&udev->dev, "Tier policy prevents U1/U2 LPM states for devices at tier %d\n",
+ tier);
+ return -E2BIG;
}
Or possibly even add a xhci->max_tier_for_lpm that can be set during probe based on
vendor or from device property.
Thanks
-Mathias
