linux/arch
Pavel Pisa ad6714230f [PATCH] Linux 2.6.x VM86 interrupt emulation fixes
Patch solves VM86 interrupt emulation deadlock on SMP systems.  The VM86
interrupt emulation has been heavily tested and works well on UP systems
after last update, but it seems to deadlock when we have used it on SMP/HT
boxes now.

It seems, that disable_irq() cannot be called from interrupts, because it
waits until disabled interrupt handler finishes
(/kernel/irq/manage.c:synchronize_irq():while(IRQ_INPROGRESS);).  This
blocks one CPU after another.  Solved by use disable_irq_nosync.

There is the second problem.  If IRQ source is fast, it is possible, that
interrupt is sometimes processed and re-enabled by the second CPU, before
it is disabled by the first one, but negative IRQ disable depths are not
allowed.  The spinlocking and disabling IRQs over call to
disable_irq_nosync/enable_irq is the only solution found reliable till now.

Signed-off-by: Michal Sojka <sojkam1@control.felk.cvut.cz>
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 08:58:52 -07:00
..
alpha [PATCH] alpha: key management syscalls 2005-04-21 11:28:26 -07:00
arm [PATCH] ARM: IntegratorCP: Fix CLCD MUX selection values 2005-04-30 23:32:38 +01:00
arm26 [PATCH] freepgt: arm26 FIRST_USER_ADDRESS PAGE_SIZE 2005-04-19 13:29:22 -07:00
cris Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
frv Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
h8300 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
i386 [PATCH] Linux 2.6.x VM86 interrupt emulation fixes 2005-05-01 08:58:52 -07:00
ia64 From: jbarnes@sgi.com 2005-04-25 13:31:04 -07:00
m32r Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
m68k [PATCH] M68k: Update defconfigs for 2.6.12-rc2 2005-04-18 10:47:34 -07:00
m68knommu Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mips [PATCH] mips: remove #include <linux/audit.h> two times 2005-04-16 15:24:41 -07:00
parisc [PATCH] add Big Endian variants of ioread/iowrite 2005-04-16 15:25:54 -07:00
ppc [PATCH] ppc32: workaround for spurious IRQs on PQ2 2005-05-01 08:58:42 -07:00
ppc64 [PATCH] ppc64: use smp_mb and smp_wmb 2005-05-01 08:58:47 -07:00
s390 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sh [PATCH] fix u32 vs. pm_message_t in rest of the tree 2005-04-16 15:25:37 -07:00
sh64 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sparc [SPARC]: dump_stack for sparc 2005-04-24 20:46:49 -07:00
sparc64 [PATCH] mostek bogus sparse annotations fixed 2005-04-24 12:28:36 -07:00
um [PATCH] uml: fix compilation for __CHOOSE_MODE addition 2005-04-16 15:25:39 -07:00
v850 Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
x86_64 [PATCH] Increase number of e820 entries hard limit from 32 to 128 2005-05-01 08:58:51 -07:00