PCI: rpaphp: Fix up pointer to first drc-info entry

BugLink: https://bugs.launchpad.net/bugs/1860816

[ Upstream commit 9723c25 ]

The first entry of the ibm,drc-info property is an int encoded count
of the number of drc-info entries that follow. The "value" pointer
returned by of_prop_next_u32() is still pointing at the this value
when we call of_read_drc_info_cell(), but the helper function
expects that value to be pointing at the first element of an entry.

Fix up by incrementing the "value" pointer to point at the first
element of the first drc-info entry prior.

Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1573449697-5448-5-git-send-email-tyreld@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/pci/hotplug/rpaphp_core.c

@@ -239,6 +239,8 @@ static int rpaphp_check_drc_props_v2(struct device_node *dn, char *drc_name,
 	value = of_prop_next_u32(info, NULL, &entries);
 	if (!value)
 		return -EINVAL;
+	else
+		value++;
 
 	for (j = 0; j < entries; j++) {
 		of_read_drc_info_cell(&info, &value, &drc);