Skip to content
Commit 935356ce authored by Dou Liyang's avatar Dou Liyang Committed by Thomas Gleixner
Browse files

x86/apic: Initialize interrupt mode after timer init



A cold or warm boot through BIOS sets the APIC in default interrupt
delivery mode. A dump-capture kernel will not go through a BIOS reset and
leave the interrupt delivery mode in the state which was active on the
crashed kernel, but the dump kernel startup code assumes default delivery
mode which can result in interrupt delivery/handling to fail.

To solve this problem, it's required to set up the final interrupt delivery
mode as soon as possible. As IOAPIC setup needs the timer initialized for
verifying the timer interrupt delivery mode, the earliest point is right
after timer setup in late_time_init().

That results in the following init order:

  1) Set up the legacy timer, if applicable on the platform

  2) Set up APIC/IOAPIC which includes the verification of the legacy timer
     interrupt delivery.

  3) TSC calibration

  4) Local APIC timer setup


Signed-off-by: default avatarDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-12-git-send-email-douly.fnst@cn.fujitsu.com
parent 34fba3e6
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment