pci: Print a warning if the bus is accessed before probing

It is not possible to access a device on a PCI bus that has not yet been
probed, since the bus number is not known. Add a warning to catch this
error.

Signed-off-by: Simon Glass <sjg@chromium.org>
This commit is contained in:
Simon Glass 2019-12-29 21:19:14 -07:00
parent 3d9acea3d9
commit 4886287ee4

View File

@ -48,6 +48,19 @@ pci_dev_t dm_pci_get_bdf(struct udevice *dev)
struct pci_child_platdata *pplat = dev_get_parent_platdata(dev);
struct udevice *bus = dev->parent;
/*
* This error indicates that @dev is a device on an unprobed PCI bus.
* The bus likely has bus=seq == -1, so the PCI_ADD_BUS() macro below
* will produce a bad BDF>
*
* A common cause of this problem is that this function is called in the
* ofdata_to_platdata() method of @dev. Accessing the PCI bus in that
* method is not allowed, since it has not yet been probed. To fix this,
* move that access to the probe() method of @dev instead.
*/
if (!device_active(bus))
log_err("PCI: Device '%s' on unprobed bus '%s'\n", dev->name,
bus->name);
return PCI_ADD_BUS(bus->seq, pplat->devfn);
}