On 2/6/23 3:27 PM, Lukas Wunner wrote:
On Mon, Feb 06, 2023 at 01:50:52PM -0700, Dave Jiang wrote:
Move the logic in current_link_speed_show() to a common function and export
that functiuon as pcie_get_speed() to allow other drivers to to retrieve
the current negotiated link speed.
[...]
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6215,6 +6215,26 @@ enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev)
}
EXPORT_SYMBOL(pcie_get_width_cap);
+/**
+ * pcie_get_speed - query for the PCI device's current link speed
+ * @dev: PCI device to query
+ *
+ * Query the PCI device current link speed.
+ */
+enum pci_bus_speed pcie_get_speed(struct pci_dev *dev)
+{
+ u16 linkstat, cls;
+ int err;
+
+ err = pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &linkstat);
+ if (err)
+ return PCI_SPEED_UNKNOWN;
+
+ cls = FIELD_GET(PCI_EXP_LNKSTA_CLS, linkstat);
+ return pcie_link_speed[cls];
+}
+EXPORT_SYMBOL(pcie_get_speed);
It seems we're already caching the current speed in dev->bus->cur_bus_speed.
Is that not sufficient? If it isn't, that should be explained in the
commit message.
I did not realize. That should work. Thanks. I'll drop patch.
Thanks,
Lukas
