linux/arch/powerpc
Thomas Gleixner b8a9a11b97 powerpc: Eeh: Kill another abuse of irq_desc
commit 91150af3a (powerpc/eeh: Fix unbalanced enable for IRQ) is
another brilliant example of trainwreck engineering.

The patch "fixes" the issue of an unbalanced call to irq_enable()
which causes a prominent warning by checking the disabled state of the
interrupt line and call conditionally into the core code.

This is wrong in two aspects:

1) The warning is there to tell users, that they need to fix their
   asymetric enable/disable patterns by finding the root cause and
   solving it there.

   It's definitely not meant to work around it by conditionally
   calling into the core code depending on the random state of the irq
   line.

   Asymetric irq_disable/enable calls are a clear sign of wrong usage
   of the interfaces which have to be cured at the root and not by
   somehow hacking around it.

2) The abuse of core internal data structure instead of using the
   proper interfaces for retrieving the information for the 'hack
   around'

   irq_desc is core internal and it's clear enough stated.

Replace at least the irq_desc abuse with the proper functions and add
a big fat comment why this is absurd and completely wrong.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Gavin Shan <shangw@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: ppc <linuxppc-dev@lists.ozlabs.org>
Link: http://lkml.kernel.org/r/20140223212736.562906212@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-03-04 17:37:52 +01:00
..
boot Merge remote-tracking branch 'agust/next' into next 2014-01-29 16:53:55 +11:00
configs Merge remote-tracking branch 'scott/next' into next 2014-01-15 14:22:35 +11:00
crypto powerpc: Fix compile of sha1-powerpc-asm.S on 32-bit 2013-03-05 16:56:26 +11:00
include powerpc/powernv: Add iommu DMA bypass support for IODA2 2014-02-11 16:07:37 +11:00
kernel powerpc: Eeh: Kill another abuse of irq_desc 2014-03-04 17:37:52 +01:00
kvm Second batch of KVM updates. Some minor x86 fixes, 2014-01-31 08:37:32 -08:00
lib powerpc: Add vr save/restore functions 2014-01-15 13:46:43 +11:00
math-emu powerpc: fix e500 SPE float SIGFPE generation 2014-01-07 18:43:42 -06:00
mm powerpc: Fix kdump hang issue on p8 with relocation on exception enabled. 2014-02-11 11:24:47 +11:00
net bpf: do not use reciprocal divide 2014-01-15 17:02:08 -08:00
oprofile powerpc: Delete non-required instances of include <linux/init.h> 2014-01-15 13:46:44 +11:00
perf powerpc/perf: Configure BHRB filter before enabling PMU interrupts 2014-02-11 11:24:50 +11:00
platforms powerpc/powernv: Add iommu DMA bypass support for IODA2 2014-02-11 16:07:37 +11:00
sysdev powerpc:eVh_pic: Kill irq_desc abuse 2014-03-04 17:37:51 +01:00
xmon powerpc/xmon: Don't signal we've entered until we're finished printing 2014-02-11 11:24:51 +11:00
Kconfig Second batch of KVM updates. Some minor x86 fixes, 2014-01-31 08:37:32 -08:00
Kconfig.debug Merge branch 'kconfig-diet' from Dave Hansen 2013-07-04 11:25:51 -07:00
Makefile powerpc: Fix error when cross building TAGS & cscope 2013-11-25 11:49:11 +11:00
relocs_check.pl Fix warning typo "CONFIG_RELCOATABLE" 2013-05-29 15:11:30 +02:00