Alex Chiang wrote:
* Matthew Wilcox <matthew@xxxxxx>:
On Fri, Jul 25, 2008 at 01:29:16AM +0200, Pierre Ossman wrote:
On Thu, 24 Jul 2008 17:08:27 -0600
Alex Chiang <achiang@xxxxxx> wrote:
Sorry for one more round-trip, but could you turn on debugging
for pciehp as well?
Same thing, with debugging:
I have a laptop with a similar problem (though I don't have pciehp
enabled, so I didn't notice it). Obviously, we need to fix this.
There is no question in my mind that firmware has programmed the slot
numbers incorrectly. Here's the evidence from lspci -vvv:
00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 1 (rev 03)
Capabilities: [40] Express (v1) Root Port (Slot+), MSI 00
SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surpise+
Slot # 2, PowerLimit 6.500000; Interlock- NoCompl-
00:1c.4 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 5 (rev 03)
Capabilities: [40] Express (v1) Root Port (Slot+), MSI 00
SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surpise+
Slot # 2, PowerLimit 6.500000; Interlock- NoCompl-
I don't think anyone can credibly argue that this is correct. They're
both PCIe devices, they're both both indicating that they have a slot
(maybe if I get my screwdriver out, I can see if there's really a slot
...), they're on the same bus (so I don't know how the with_bus
parameter makes any difference).
I've always hated that with_bus parameter. I don't like it being a
parameter and I don't like the names it produces.
Part of the problem is the kobject API. It really hates you trying to
register a duplicate name and won't just return -EEXIST and let you try
a new name. Instead it prints an ugly warning and dumps stack. See
kobject_add_internal() in lib/kobject.c.
Yeah, I don't really like that part of the kobject API either.
So we need a way to find if there's already a slot of this name. I
don't see a kobject routine to do that. Maybe we can do it internally
to the pci slot code.
Well, we have this code in pci_hp_register:
/* Check if we have already registered a slot with the same name. */
if (get_slot_from_name(slot->name))
return -EEXIST;
Then we need to pick a new name for the kobject if it does collide.
My suggestion is that the second time we find an object named "2", we
call it "2dup1" (the third time "2dup2", etc.) Other opinions I've
seen include "2a", "2b", ... or "2-1", "2-2", ... or "2-brokenfw1",
"2-brokenfw2".
I'm at OLS this week, so no patch from me.
It should be pretty easy for pci_hp_register() to fix up the name
in the event of a collision.
The hard part is figuring out a convention that we can all agree
on. ;) I've no strong feelings here, but of the options
presented, I lean towards "2a", "2b" or "2-1", "2-2".
Only my hope is I don't want to look "2a" or "2-1" on normal platform.
It should be "2" on normal platform.
I'd like to try to make a patch, but it will be middle of next week
because of other jobs. Is that ok?
Thanks,
Kenji Kaneshige
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
