lkml.org 
[lkml]   [2008]   [Apr]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/2] pci/irq: restore mask_bits in msi shutdown -v3
On Wed, Apr 23, 2008 at 2:56 PM, Yinghai Lu <yhlu.kernel.send@gmail.com> wrote:
>
> Yinghai found after using 2.6.25-rc3 later to kexec RHEL 5.1,
> NIC can not be used.
>
> bisected to
>
> | commit 89d694b9dbe769ca1004e01db0ca43964806a611
> | Author: Thomas Gleixner <tglx@linutronix.de>
> | Date: Mon Feb 18 18:25:17 2008 +0100
> |
> | genirq: do not leave interupts enabled on free_irq
> |
> | The default_disable() function was changed in commit:
> |
> | 76d2160147f43f982dfe881404cfde9fd0a9da21
> | genirq: do not mask interrupts by default
> |
> | It removed the mask function in favour of the default delayed
> | interrupt disabling. Unfortunately this also broke the shutdown in
> | free_irq() when the last handler is removed from the interrupt for
> | those architectures which rely on the default implementations. Now we
> | can end up with a enabled interrupt line after the last handler was
> | removed, which can result in spurious interrupts.
> |
> | Fix this by adding a default_shutdown function, which is only
> | installed, when the irqchip implementation does provide neither a
> | shutdown nor a disable function.
> |
> | [@stable: affected versions: .21 - .24 ]
>
> for MSI, default_shutdown will call mask_bit for msi device. so all mask bits
> will left disabled after free_irq. then if kexec next kernel that only can
> use msi_enable bit. all device's MSI can not be used.
>
> want to try to restore MSI mask bits that is saved before using msi in first
> kernel.
>
> Eric said:
> This is over complicated and for hardware that erroneously triggers
> a msi irq after free_irq may have potential problems.
>
> So lets do the much simpler, much safer, and more general method of
> restoring the mask bit to it's pci reset defined value (enabled) when
> we disable the kernels use of msi.
>
> it will work, because pci_diable_msi is called after free_irq is called.
>
> v3: extend msi_set_mask_bit to msi_set_mask_bits to take mask, so we can fully
> restore that to 0x00 instead of 0xfe.
>
> Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>

andrew,

this one should replace

[PATCH] x86_64: restore mask_bits in msi shutdown

in -mm

YH


\
 
 \ /
  Last update: 2008-04-25 02:43    [from the cache]
©2003-2011 Jasper Spaans. Advertise on this site