| Message ID | 540E1D75.5000500@gmail.com |
|---|---|
| State | Accepted |
| Headers | show |
On Mon, Sep 08, 2014 at 02:19:49PM -0700, Rajat Jain wrote: > Some root ports may return the actual device id returned by the > endpoint, instead of faking up a synthetic id (0xFFFF) as specified > by the PCIe spec (sec 2.3.2). We have seen such broken devices in the > past that match this behaviour: > (Ref: https://lkml.org/lkml/2007/11/1/198) > > To take care of the same, CRS was disabled then, however, we want to > enable CRS now (https://lkml.org/lkml/2014/9/2/509), but still do not > want to break such devices. Thus check only against the > (vendor id == 1) and ignore the device id. > > Signed-off-by: Rajat Jain <rajatxjain@gmail.com> > Signed-off-by: Rajat Jain <rajatjain@juniper.net> > Signed-off-by: Guenter Roeck <groeck@juniper.net> Applied to pci/enumeration for v3.18, thanks! > --- > drivers/pci/probe.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 3c4c35c..0076a9b 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -1305,8 +1305,13 @@ bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, > *l == 0x0000ffff || *l == 0xffff0000) > return false; > > - /* Configuration request Retry Status */ > - while (*l == 0xffff0001) { > + /* > + * Configuration request Retry Status. Note that some root ports > + * are broken and may return actual device ID instead of a synthetic ID > + * (0xFFFF) to be faked as per the PCIe spec. Hence ignore the device ID > + * and only check for (vendor id == 1) > + */ > + while (*l & 0xffff == 0x0001) { > if (!crs_timeout) > return false; > > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 3c4c35c..0076a9b 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1305,8 +1305,13 @@ bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, *l == 0x0000ffff || *l == 0xffff0000) return false; - /* Configuration request Retry Status */ - while (*l == 0xffff0001) { + /* + * Configuration request Retry Status. Note that some root ports + * are broken and may return actual device ID instead of a synthetic ID + * (0xFFFF) to be faked as per the PCIe spec. Hence ignore the device ID + * and only check for (vendor id == 1) + */ + while (*l & 0xffff == 0x0001) { if (!crs_timeout) return false;