From: Subbaraya Sundeep <sbha...@marvell.com>
As per the spec, "Enhanced Allocation (EA) for Memory
and I/O Resources" ECN, approved 23 October 2014,
sec 6.9.1.2, fixed bus numbers of a bridge can be zero
when no function that uses EA is located behind it.
Hence assign bus numbers sequentially when fixed bus
numbers are zero.
Fixes: 2dbce590117981196fe355efc0569bc6f949ae9b
Signed-off-by: Subbaraya Sundeep <sbha...@marvell.com>
---
drivers/pci/probe.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index a3c7338..c06ca4c 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1095,27 +1095,28 @@ static unsigned int pci_scan_child_bus_extend(struct
pci_bus *bus,
* @sub: updated with subordinate bus number from EA
*
* If @dev is a bridge with EA capability, update @sec and @sub with
- * fixed bus numbers from the capability and return true. Otherwise,
- * return false.
+ * fixed bus numbers from the capability. Otherwise @sec and @sub
+ * will be zeroed.
*/
-static bool pci_ea_fixed_busnrs(struct pci_dev *dev, u8 *sec, u8 *sub)
+static void pci_ea_fixed_busnrs(struct pci_dev *dev, u8 *sec, u8 *sub)
{
int ea, offset;
u32 dw;
+ *sec = *sub = 0;
+
if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE)
- return false;
+ return;
/* find PCI EA capability in list */
ea = pci_find_capability(dev, PCI_CAP_ID_EA);
if (!ea)
- return false;
+ return;
offset = ea + PCI_EA_FIRST_ENT;
pci_read_config_dword(dev, offset, &dw);
*sec = dw & PCI_EA_SEC_BUS_MASK;
*sub = (dw & PCI_EA_SUB_BUS_MASK) >> PCI_EA_SUB_BUS_SHIFT;
- return true;
}
/*
@@ -1151,7 +1152,6 @@ static int pci_scan_bridge_extend(struct pci_bus *bus,
struct pci_dev *dev,
u16 bctl;
u8 primary, secondary, subordinate;
int broken = 0;
- bool fixed_buses;
u8 fixed_sec, fixed_sub;
int next_busnr;
@@ -1254,11 +1254,12 @@ static int pci_scan_bridge_extend(struct pci_bus *bus,
struct pci_dev *dev,
pci_write_config_word(dev, PCI_STATUS, 0xffff);
/* Read bus numbers from EA Capability (if present) */
- fixed_buses = pci_ea_fixed_busnrs(dev, &fixed_sec, &fixed_sub);
- if (fixed_buses)
+ pci_ea_fixed_busnrs(dev, &fixed_sec, &fixed_sub);
+
+ next_busnr = max + 1;
+ /* Use secondary bus number in EA */
+ if (fixed_sec)
next_busnr = fixed_sec;
- else
- next_busnr = max + 1;
/*
* Prevent assigning a bus number that already exists.
@@ -1336,7 +1337,7 @@ static int pci_scan_bridge_extend(struct pci_bus *bus,
struct pci_dev *dev,
* If fixed subordinate bus number exists from EA
* capability then use it.
*/
- if (fixed_buses)
+ if (fixed_sub)
max = fixed_sub;
pci_bus_update_busn_res_end(child, max);
pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max);
--
2.7.4
