> That is a tricky issue. Sometimes the slightest things can set
> something like this off.
>
> Somewhere someone changed something in one of the drivers that made it
> so that the hardware winds up in a state the int 13 disk driver does not
> like it after kexec.
> .
> If you want to track this down I would recommend a bisect between 3.4
> and 3.5-rc1 to see which change breaks your setup.
I bistcted that down to this patch:
commit b566a22c23327f18ce941ffad0ca907e50a53d41
Author: Khalid Aziz <khalid.aziz at hp.com>
Date: Fri Apr 27 13:00:33 2012 -0600
PCI: disable Bus Master on PCI device shutdown
Disable Bus Master bit on the device in pci_device_shutdown() to ensure PCI
devices do not continue to DMA data after shutdown. This can cause memory
corruption in case of a kexec where the current kernel shuts down and
transfers control to a new kernel while a PCI device continues to DMA to
memory that does not belong to it any more in the new kernel.
I have tested this code on two laptops, two workstations and a 16-socket
server. kexec worked correctly on all of them.
Signed-off-by: Khalid Aziz <khalid.aziz at hp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
Without this patch, int13 works fine here! If anyone needs more information, just let me know!
Greetings,
Christian
