On Thu, May 01, 2014 at 05:35:48PM +0300, Marcel Apfelbaum wrote:
> When a board is added, the shpchp driver checks if there
> is a mismatch between the bridge's adapter and the bus speed.
> If there is, it sets the subordinate speed (if there is no device on it).
>
> However, it takes the reference of the board speed from the primary bus
> and not from the subordinate. If the primary bus is PCI and not PCIX/PCIe,
> its speed is not updated and remains 0xff. As a result hotplug fails
> with error: "Speed of bus ff and adapter 0 mismatch".
>
> Fixed that by checking the speed against the subordinate bus.
>
> Signed-off-by: Marcel Apfelbaum <marcel.a@xxxxxxxxxx>
> Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
I think cpqphp has similar issues. But I can't test it and I don't know if
anybody even uses it any more, so I'm just going to leave it alone.
I reworked the changelog because I got confused about the bridge, adapter,
board, and what was what. Let me know if the one below is inaccurate.
I'll include this for v3.15 since it's a regression fix.
Thanks,
Bjorn
commit be219b7f518a36f62d67f057e9d31ebe9674814f
Author: Marcel Apfelbaum <marcel.a@xxxxxxxxxx>
Date: Thu May 1 17:35:48 2014 +0300
PCI: shpchp: Check bridge's secondary (not primary) bus speed
When a new device is added below a hotplug bridge, the bridge's secondary
bus speed and the device's bus speed must match. The shpchp driver
previously checked the bridge's *primary* bus speed, not the secondary bus
speed.
This caused hot-add errors like:
shpchp 0000:00:03.0: Speed of bus ff and adapter 0 mismatch
Check the secondary bus speed instead.
[bhelgaas: changelog]
Link: https://bugzilla.kernel.org/show_bug.cgi?id=75251
Fixes: 3749c51ac6c1 ("PCI: Make current and maximum bus speeds part of the PCI core")
Signed-off-by: Marcel Apfelbaum <marcel.a@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx # v2.6.34+
diff --git a/drivers/pci/hotplug/shpchp_ctrl.c b/drivers/pci/hotplug/shpchp_ctrl.c
index 58499277903a..6efc2ec5e4db 100644
--- a/drivers/pci/hotplug/shpchp_ctrl.c
+++ b/drivers/pci/hotplug/shpchp_ctrl.c
@@ -282,8 +282,8 @@ static int board_added(struct slot *p_slot)
return WRONG_BUS_FREQUENCY;
}
- bsp = ctrl->pci_dev->bus->cur_bus_speed;
- msp = ctrl->pci_dev->bus->max_bus_speed;
+ bsp = ctrl->pci_dev->subordinate->cur_bus_speed;
+ msp = ctrl->pci_dev->subordinate->max_bus_speed;
/* Check if there are other slots or devices on the same bus */
if (!list_empty(&ctrl->pci_dev->subordinate->devices))
--
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