Check PCI-e link width to avoid foot shooting with 4x links

MFC after: 3 days
This commit is contained in:
Kip Macy 2007-03-23 20:18:07 +00:00
parent 302ce8d690
commit fc01c613c5

View File

@ -303,13 +303,29 @@ cxgb_controller_attach(device_t dev)
device_t child;
const struct adapter_info *ai;
struct adapter *sc;
int i, msi_needed, msi_count = 0, error = 0;
int i, reg, msi_needed, msi_count = 0, error = 0;
uint32_t vers;
int port_qsets = 1;
sc = device_get_softc(dev);
sc->dev = dev;
/* find the PCIe link width and set max read request to 4KB*/
if (pci_find_extcap(dev, PCIY_EXPRESS, &reg) == 0) {
uint16_t lnk, pectl;
lnk = pci_read_config(dev, reg + 0x12, 2);
sc->link_width = (lnk >> 4) & 0x3f;
pectl = pci_read_config(dev, reg + 0x8, 2);
pectl = (pectl & ~0x7000) | (5 << 12);
pci_write_config(dev, reg + 0x8, pectl, 2);
}
if (sc->link_width != 0 && sc->link_width <= 4) {
device_printf(sc->dev,
"PCIe x%ld Link, expect reduced performance\n",
sc->link_width);
}
pci_enable_busmaster(dev);
/*