linux-stable/arch
David S. Miller d0cac39e4e sparc64: Fix lost interrupts on sun4u.
Based upon a report by Meelis Roos.

Sparc64 SBUS and PCI controllers use a combination of IMAP and ICLR
registers to manage device interrupts.

The IMAP register contains the "valid" enable bit as well as CPU
targetting information.  Whereas the ICLR register is written with
zero at the end of handling an interrupt to reset the state machine
for that interrupt to IDLE so it can be sent again.

For PCI slot and SBUS slot devices we can have multiple interrupts
sharing the same IMAP register.  There are individual ICLR registers
but only one IMAP register for managing those.

We represent each shared case with individual virtual IRQs so the
generic IRQ layer thinks there is only one user of the IRQ instance.

In such shared IMAP cases this is wrong, so if there are multiple
active users then a free_irq() call will prematurely turn off the
interrupt by clearing the Valid bit in the IMAP register even though
there are other active users.

Fix this by simply doing nothing in sun4u_disable_irq() and checking
IRQF_DISABLED during IRQ dispatch.

This situation doesn't exist in the hypervisor sun4v cases, so I left
those alone.

Tested-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-04 14:43:47 -08:00
..
alpha alpha: fixup BUG macro 2009-02-05 12:56:49 -08:00
arm Merge master.kernel.org:/home/rmk/linux-2.6-arm 2009-02-03 16:52:10 -08:00
avr32 eeprom: More consistent symbol names 2009-01-26 21:19:57 +01:00
blackfin Blackfin arch: Remove outdated code 2009-02-04 16:49:45 +08:00
cris Merge branch 'syscalls' of git://git390.osdl.marist.edu/pub/scm/linux-2.6 2009-01-14 19:58:40 -08:00
frv FRV: in_interrupt() requires #inclusion of linux/hardirq.h not asm/hardirq.h now 2009-02-09 08:51:35 -08:00
h8300 Merge branch 'syscalls' of git://git390.osdl.marist.edu/pub/scm/linux-2.6 2009-01-14 19:58:40 -08:00
ia64 PCI: return error on failure to read PCI ROMs 2009-02-04 16:58:41 -08:00
m32r eeprom: More consistent symbol names 2009-01-26 21:19:57 +01:00
m68k m68knommu: remove the no longer used PCI support option 2009-01-27 16:42:02 +10:00
m68knommu m68knommu: fix 5329 ColdFire periphal addressing 2009-01-27 16:42:03 +10:00
mips x86: spinlocks: define dummy __raw_spin_is_contended 2009-02-09 08:15:39 -08:00
mn10300 [CVE-2009-0029] Rename old_readdir to sys_old_readdir 2009-01-14 14:15:15 +01:00
parisc Documentation: move DMA-mapping.txt to Doc/PCI/ 2009-01-29 18:19:29 -08:00
powerpc powerpc: Add missing sparsemem.h include 2009-02-10 14:39:09 +11:00
s390 [S390] Add missing compat system call wrappers. 2009-01-23 16:40:29 +01:00
sh sh: Fix up T-bit error handling in SH-4A mutex fastpath. 2009-01-29 11:56:03 +09:00
sparc sparc64: Fix lost interrupts on sun4u. 2009-03-04 14:43:47 -08:00
um mm: invoke oom-killer from page fault 2009-01-06 15:58:58 -08:00
x86 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq 2009-02-09 13:58:22 -08:00
xtensa byteorder: make swab.h include asm/swab.h like a regular header 2009-01-14 19:56:50 -08:00
.gitignore
Kconfig [CVE-2009-0029] System call wrapper infrastructure 2009-01-14 14:15:16 +01:00