michaelh/zephyr
1
0
Fork 0
Code Releases Activity

quark_se: apic: work around EOI forwarding issue

Browse source 
Quark SE Lakemont core has a hardware bug where the LOAPIC does
not properly notify the IOAPIC to clear the IRR bit for level-
triggered interrupts.

This patch introduces a workaround where the vector ID of the
in-service interrupt is manually written to the IOAPIC_EOI
register, resulting in the bit being cleared.

Unfortunately, in the context where EOI happens it's very difficult
to identify which IRQ line is being serviced, so this is done
unconditionally for all interrupts vectors whether they are registered
in the IOAPIC RTE table or not.

Change-Id: I639cd258dec4f50934e17eadbb821e6a7112e636
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
This commit is contained in:
Andrew Boie 2015-12-10 14:43:10 -08:00 • committed by Anas Nashif
commit 88808f1247
6 changed files with 124 additions and 39 deletions
Download patch file Download diff file Expand all files Collapse all files

7
arch/x86/platforms/quark_se/Kconfig
View file

@ -41,6 +41,13 @@ config IOAPIC_NUM_RTES
config LOAPIC_TIMER_IRQ
default 64
config EOI_FORWARDING_BUG
bool
default y
help
Quark SE LOAPIC has issues with forwarding EOI to the IOAPIC for level
triggered interrupts, this is a SW workaround.
if PINMUX
config PINMUX_BASE
default 0xB0800930