Re: [PATCH 0/7] Fixups for duplicate slot names

From: Kenji Kaneshige
Date: Thu Aug 07 2008 - 04:44:29 EST


Hi Alex-san,

Thank you for patches!

I looked at your patches and it looks good. But I have only one
concern about how to allocate/free memory for slot name.

With your change, memory region for slot name will be allocated
by hotplug *controller* driver and it can be freed using kfree()
by hotplug *core* driver (not hotplug controller driver). So all
hotplug controller drivers including drivers implemented in the
future need to take it into account.

I think it will be more robust if we can allocate and free memory
in the same component (maybe hotplug core driver in this case).

Thanks,
Kenji Kaneshige


Alex Chiang wrote:
* Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx>:
With this change, kobject_init_and_add() called in
pci_create_slot() will show stack trace if a hotplug driver
attempts to register multiple slot with the same name. That is,
stack trace will be shown on the platform that wrongly assing
the physical slot number to multiple slots. I'm very sorry, but
I don't have enough time to consider how to fix it today.

Hello Kenji-san,

You are obviously correct about my prior bad patch that simply
removed the check in pci_hp_register() for duplicate names.

I also talked with Willy, and he thought that the proper way to
fix all these issues was not in the individual drivers, but in
the PCI core, which I agree with.

Here is a patch series that attempts to implement Willy's
suggestion.

Patches 1--6 convert the callers of pci_hp_register/pci_create_slot
from a static char name[] to a dynamically kmalloc'ed char *name.

There are also cleanups in the individual drivers to remove the
_slot_with_bus parameters.

Patch 7/7 implements the collision rename logic. It's not the
prettiest thing in the world, so your comments are welcome. :)

It's getting late here and I haven't had time to really test it,
other than a quick compile test, but I wanted to try and send it
so that you could take a look and possibly try it. ;)

These patches apply on top of Linus's latest tree.

Thanks!

/ac

drivers/acpi/pci_slot.c | 15 ++++++-
drivers/pci/hotplug/acpiphp.h | 2 -
drivers/pci/hotplug/acpiphp_core.c | 18 +++++----
drivers/pci/hotplug/fakephp.c | 16 ++++++--
drivers/pci/hotplug/pci_hotplug_core.c | 4 --
drivers/pci/hotplug/pciehp.h | 6 +--
drivers/pci/hotplug/pciehp_core.c | 7 ---
drivers/pci/hotplug/pciehp_hpc.c | 19 ++++-----
drivers/pci/hotplug/pcihp_skeleton.c | 12 ++++--
drivers/pci/hotplug/shpchp.h | 5 +-
drivers/pci/hotplug/shpchp_core.c | 29 ++++----------
drivers/pci/slot.c | 65 +++++++++++++++++++++++++++++----
include/linux/pci.h | 3 -
13 files changed, 124 insertions(+), 77 deletions(-)

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