The previous patch of this type fixed the case where a PCI device is behind an SSB->PCI bridge as found on an embedded device. This one treats the normal case of a "normal" Broadcom wireless PCI core on an SSB interconnect. MMIO log traces obtained using the Broadcom wl hybrid driver show that the RETRY_TIMEOUT register (0x41) in PCI configuration space is cleared if non-zero. Similar code found in other drivers such as ipw2100 show this operation is needed to keep PCI Tx retries from interfering with C3 CPU state. There are no known cases where omission of this code has caused a problem, but this patch is offered just in case such a situation occurs. Signed-off-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx> --- John, No particular urgency for this patch. Larry --- Index: wireless-testing/drivers/ssb/pcihost_wrapper.c =================================================================== --- wireless-testing.orig/drivers/ssb/pcihost_wrapper.c +++ wireless-testing/drivers/ssb/pcihost_wrapper.c @@ -59,6 +59,7 @@ static int ssb_pcihost_probe(struct pci_ struct ssb_bus *ssb; int err = -ENOMEM; const char *name; + u32 val; ssb = kzalloc(sizeof(*ssb), GFP_KERNEL); if (!ssb) @@ -74,6 +75,12 @@ static int ssb_pcihost_probe(struct pci_ goto err_pci_disable; pci_set_master(dev); + /* Disable the RETRY_TIMEOUT register (0x41) to keep + * PCI Tx retries from interfering with C3 CPU state */ + pci_read_config_dword(dev, 0x40, &val); + if ((val & 0x0000ff00) != 0) + pci_write_config_dword(dev, 0x40, val & 0xffff00ff); + err = ssb_bus_pcibus_register(ssb, dev); if (err) goto err_pci_release_regions; -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
