Re: [patch] properly stop devices before poweroff

[Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>]

Hi,

Andrew Morton wrote:
> Pavel Machek <pavel@ucw.cz> wrote:
>
> > Without this patch, Linux provokes emergency disk shutdowns and
> > similar nastiness. It was in SuSE kernels for some time, IIRC.
>
>
> With this patch when running `halt -p' my ia64 Tiger (using
> tiger_defconfig) gets a stream of badnesses in iosapic_unregister_intr()
> and then hangs up.
>
> Unfortunately it all seems to happen after the serial port has been
> disabled because nothing comes out.  I set the console to a squitty font
> and took a piccy.  See
> http://www.zip.com.au/~akpm/linux/patches/stuff/dsc02505.jpg
>
> I guess it's an ia64 problem.  I'll leave the patch in -mm for now.

I guess the stream of badness was occured as follows:

   pcibios_disable_device() for ia64 assumes that pci_enable_device()
   and pci_disable_device() are balanced. But with 'properly stop
   devices before power off' patch, pci_disable_device() becomes to be
   called twice for e1000 device at halt time, through reboot_notifier_list
   callback and through device_suspend(). As a result, iosapic_unregister_intr()
   was called for already unregistered gsi and then stream of badness
   was displayed.

I think the following patch will remove this stream of badness. I'm
sorry but I have not checked if the stream of badness is actually
removed because I'm on vacation and I can't look at my display
(I'm working via remote console). Could you try this patch?

By the way, I don't think this stream of badness is related to hang up,
because the problem (hang up) was reproduced even on my test kernel that
doesn't call pcibios_disable_device().

Thanks,
Kenji Kaneshige
---


There might be some cases that pci_disable_device() is called even if
the device is already disabled. In this case, pcibios_disable_device()
should not call acpi_pci_irq_disable() for the device.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>


---

linux-2.6.12-rc3-mm2-kanesige/arch/ia64/pci/pci.c |    3 ++-
1 files changed, 2 insertions(+), 1 deletion(-)

diff -puN arch/ia64/pci/pci.c~fix_pcibios_disable_device_ia64 arch/ia64/pci/pci.c
--- linux-2.6.12-rc3-mm2/arch/ia64/pci/pci.c~fix_pcibios_disable_device_ia64	2005-05-02 03:12:23.000000000 +0900
+++ linux-2.6.12-rc3-mm2-kanesige/arch/ia64/pci/pci.c	2005-05-02 03:12:23.000000000 +0900
@@ -512,7 +512,8 @@ pcibios_enable_device (struct pci_dev *d
void
pcibios_disable_device (struct pci_dev *dev)
{
-	acpi_pci_irq_disable(dev);
+	if (dev->is_enabled)
+		acpi_pci_irq_disable(dev);
}
#endif /* CONFIG_ACPI_DEALLOCATE_IRQ */


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