[patch 10/10] Fix incorrect handling PCI-Express Root Bridge _HID

[patch 10/10] Fix incorrect handling PCI-Express Root Bridge _HID

[akpm]

From: <eiichiro.oiwa.nm@hitachi.com>

Lifted from http://bugzilla.kernel.org/show_bug.cgi?id=7145

PCI Bus Topology:

[CPU] [CPU]        [CPU]  [CPU]
  |      |BUS        |     |   BUS
--+--+---+---      --+--+--+------
     |                  |
 [Root Bridge]*1-----[Root Bridge]*1
     |      |           \        \
 [Bridge]   |        [PCI-e slot] [PCI-e slot]
    | |    [PCI-e slot]
    | \
    | [PCI-e slot]
    |
    |
 [PCI Bridge]
    |     \
    |      [PCI-X slot]
    |
 [PCI-X slot]

*1: PCI Express Root Bridge.

I could not get correct PCI Express BUS number from the structure of
acpi_object_extra.  I always get zero as BUS number regardless of BUS
location.  I found that there is incorrect comparison with _HID (PNP0A08)
in acpi/events/evrgnini.c and PCI Express _BBN method always fail. 
Therefore, we get always get zero as PCI Express bus number.

I suggest the following patch.

Cc: "Brown, Len" <len.brown@intel.com>
Cc: <linux-acpi@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 drivers/acpi/events/evrgnini.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff -puN drivers/acpi/events/evrgnini.c~fix-incorrect-handling-of-pci-express-root-bridge-_hid drivers/acpi/events/evrgnini.c
--- a/drivers/acpi/events/evrgnini.c~fix-incorrect-handling-of-pci-express-root-bridge-_hid
+++ a/drivers/acpi/events/evrgnini.c
@@ -225,12 +225,12 @@ acpi_ev_pci_config_region_setup(acpi_han
 				if (!
 				    (ACPI_STRNCMP
 				     (object_hID.value, PCI_ROOT_HID_STRING,
-				      sizeof(PCI_ROOT_HID_STRING))
+				      sizeof(PCI_ROOT_HID_STRING)))
 				     ||
 				     !(ACPI_STRNCMP
 				       (object_hID.value,
 					PCI_EXPRESS_ROOT_HID_STRING,
-					sizeof(PCI_EXPRESS_ROOT_HID_STRING)))))
+					sizeof(PCI_EXPRESS_ROOT_HID_STRING))))
 				{
 
 					/* Install a handler for this PCI root bridge */
_

Re:[patch 10/10] Fix incorrect handling PCI-Express Root Bridge _HID

[eiichiro.oiwa.nm]

Hi Andrew,

We need this patch for APCI hotplug because APCI parser gets bus number from acpi_object_extra. I already tested this patch by ACPI hotplug, and confirmed there is no problem on our box has described PCI topology.
I don't have git rights.
Could you merge this patch into Linus's tree?

Thanks,
Eiichiro Oiwa

>From: <eiichiro.oiwa.nm@hitachi.com>
>
>Lifted from http://bugzilla.kernel.org/show_bug.cgi?id=7145
>
>PCI Bus Topology:
>
>[CPU] [CPU]        [CPU]  [CPU]
>  |      |BUS        |     |   BUS
>--+--+---+---      --+--+--+------
>     |                  |
> [Root Bridge]*1-----[Root Bridge]*1
>     |      |           \        \
> [Bridge]   |        [PCI-e slot] [PCI-e slot]
>    | |    [PCI-e slot]
>    | \
>    | [PCI-e slot]
>    |
>    |
> [PCI Bridge]
>    |     \
>    |      [PCI-X slot]
>    |
> [PCI-X slot]
>
>*1: PCI Express Root Bridge.
>
>I could not get correct PCI Express BUS number from the structure of
>acpi_object_extra.  I always get zero as BUS number regardless of BUS
>location.  I found that there is incorrect comparison with _HID (PNP0A08)
>in acpi/events/evrgnini.c and PCI Express _BBN method always fail. 
>Therefore, we get always get zero as PCI Express bus number.
>
>I suggest the following patch.
>
>Cc: "Brown, Len" <len.brown@intel.com>
>Cc: <linux-acpi@vger.kernel.org>
>Signed-off-by: Andrew Morton <akpm@osdl.org>
>---
>
> drivers/acpi/events/evrgnini.c |    4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
>diff -puN drivers/acpi/events/evrgnini.c~fix-incorrect-handling-of-pci-express-root-bridge-_hid drivers/acpi/events/evrgnini.c
>--- a/drivers/acpi/events/evrgnini.c~fix-incorrect-handling-of-pci-express-root-bridge-_hid
>+++ a/drivers/acpi/events/evrgnini.c
>@@ -225,12 +225,12 @@ acpi_ev_pci_config_region_setup(acpi_han
> 				if (!
> 				    (ACPI_STRNCMP
> 				     (object_hID.value, PCI_ROOT_HID_STRING,
>-				      sizeof(PCI_ROOT_HID_STRING))
>+				      sizeof(PCI_ROOT_HID_STRING)))
> 				     ||
> 				     !(ACPI_STRNCMP
> 				       (object_hID.value,
> 					PCI_EXPRESS_ROOT_HID_STRING,
>-					sizeof(PCI_EXPRESS_ROOT_HID_STRING)))))
>+					sizeof(PCI_EXPRESS_ROOT_HID_STRING))))
> 				{
> 
> 					/* Install a handler for this PCI root bridge */
>_
>

Re: [patch 10/10] Fix incorrect handling PCI-Express Root Bridge _HID

[Len Brown]

On Tuesday 26 September 2006 00:41, eiichiro.oiwa.nm@hitachi.com wrote:
> Hi Andrew,
> 
> We need this patch for APCI hotplug because APCI parser gets bus number from acpi_object_extra. I already tested this patch by ACPI hotplug, and confirmed there is no problem on our box has described PCI topology.
> I don't have git rights.
> Could you merge this patch into Linus's tree?

Eiichiro,
Thank you for finding and fixing this bug.
This patch is checked into the upstream ACPICA source tree.
While I don't expect to pull that whole tree into 2.6.18,
I do plan to cherry pick this patch with some others for 2.6.19,
as well as 2.6.18.stable.

thanks,
-Len

Re[2]: [patch 10/10] Fix incorrect handling PCI-Express Root Bridge _HID

[eiichiro.oiwa.nm]

>> Hi Andrew,
>> 
>> We need this patch for APCI hotplug because APCI parser gets bus number from acpi_object_extra. I already tested this patch by ACPI hotplug, and confirmed there is no problem on our box has described PCI topology.
>> I don't have git rights.
>> Could you merge this patch into Linus's tree?
>
>Eiichiro,
>Thank you for finding and fixing this bug.
>This patch is checked into the upstream ACPICA source tree.
>While I don't expect to pull that whole tree into 2.6.18,
>I do plan to cherry pick this patch with some others for 2.6.19,
>as well as 2.6.18.stable.
>
>thanks,
>-Len

Len,
Thank you for your information.

Eiichiro