[PATCH 0/2] Alchemy: fix interrupt routing

[PATCH 0/2] Alchemy: fix interrupt routing

[Sergei Shtylyov]

Hello.

   The two following patches together fix the interrupt routing currently broken
and causing boot failure with such messages:

unexpected IRQ # 8
irq 8, desc: 80406dd0, depth: 1, count: 0, unhandled: 0
->handle_irq():  80157d70, handle_bad_irq+0x0/0x38c
->chip(): 804016d0, 0x804016d0
->action(): 00000000
  IRQ_DISABLED set

   The patches are against the Linus' tree...

WBR, Sergei

Re: [PATCH 0/2] Alchemy: fix interrupt routing

[Manuel Lauss]

Sergei,

Sergei Shtylyov schrieb:
> Hello.
> 
>    The two following patches together fix the interrupt routing currently broken
> and causing boot failure with such messages:
> 
> unexpected IRQ # 8
> irq 8, desc: 80406dd0, depth: 1, count: 0, unhandled: 0
> ->handle_irq():  80157d70, handle_bad_irq+0x0/0x38c
> ->chip(): 804016d0, 0x804016d0
> ->action(): 00000000
>   IRQ_DISABLED set
> 
>    The patches are against the Linus' tree...
> 
> WBR, Sergei

Thanks a billion!
Finally I can boot linux-2.6.24-rc on my Au1200 again!

-- 
Manuel Lauss
HSSE / FH Hagenberg

Re: [PATCH 0/2] Alchemy: fix interrupt routing

[Ralf Baechle]

On Wed, Dec 05, 2007 at 05:39:10PM +0100, Manuel Lauss wrote:

> Thanks a billion!
> Finally I can boot linux-2.6.24-rc on my Au1200 again!

And with a bit of luck Alchemy will now support tickless, too.

  Ralf

Re: [PATCH 0/2] Alchemy: fix interrupt routing

[Sergei Shtylyov]

Ralf Baechle wrote:

>>Thanks a billion!
>>Finally I can boot linux-2.6.24-rc on my Au1200 again!

> And with a bit of luck Alchemy will now support tickless, too.

    Sigh. If only it had working PCI... :-(

>   Ralf

WBR, Sergei

Re: [PATCH 0/2] Alchemy: fix interrupt routing

[Sergei Shtylyov]

Ralf Baechle wrote:

>>Thanks a billion!
>>Finally I can boot linux-2.6.24-rc on my Au1200 again!

> And with a bit of luck Alchemy will now support tickless, too.

    It works:

Timer Stats Version: v0.2
Sample period: 8.024 s
     8,     1 swapper          __netdev_watchdog_up (dev_watchdog)
     8,     1 swapper          phy_connect (phy_timer)
     8,     1 swapper          phy_connect (phy_timer)
     7,     0 swapper          receive_chars (delayed_work_timer_fn)
     1,     1 swapper          cache_register (delayed_work_timer_fn)
     1,     1 swapper          neigh_table_init_no_netlink (neigh_periodic_timer)
     4,     1 swapper          queue_delayed_work_on (delayed_work_timer_fn)
     2,   866 mvltd            schedule_timeout (process_timeout)
     1,     0 swapper          page_writeback_init (wb_timer_fn)
     1,     1 init             schedule_timeout (process_timeout)
41 total events, 5.109 events/sec

>   Ralf

WBR, Sergei

Re: [PATCH 0/2] Alchemy: fix interrupt routing

[Ralf Baechle]

On Wed, Dec 05, 2007 at 09:57:24PM +0300, Sergei Shtylyov wrote:

>    It works:

> 41 total events, 5.109 events/sec

That's the expected behaviour, good.

One of the remaining problems on some platforms with tickless kernels is
that not all clocksource / clockevent driver combinations are playing
nicely with each other.  You can switch the clocksource driver manually
at runtime.  First let's see what clocksource we have:

  # cd /sys/devices/system/clocksource/clocksource0/
  # cat available_clocksource 
  MIPS pit jiffies 
  # cat current_clocksource 
  MIPS 

MIPS is the CP0 count register.  pit is the i8259 and jiffies simply counts
interrupts like in the old days so has problems with lost timer interrupts
and generally not such a great idea for tickless.  You should be able to
switch between all these drivers by something like:

  # echo jiffies > current_clocksource
  Time: jiffies clocksource has been installed.
  #

Try switching between all the available clocksources a few times to see if
that's working right also.

   Ralf

Re: [PATCH 0/2] Alchemy: fix interrupt routing

[Sergei Shtylyov]

Ralf Baechle wrote:

>>   It works:

>>41 total events, 5.109 events/sec

> That's the expected behaviour, good.

> One of the remaining problems on some platforms with tickless kernels is
> that not all clocksource / clockevent driver combinations are playing
> nicely with each other.  You can switch the clocksource driver manually
> at runtime.  First let's see what clocksource we have:
> 
>   # cd /sys/devices/system/clocksource/clocksource0/
>   # cat available_clocksource 
>   MIPS pit jiffies 

    I only have MIPS and jiffies of course. :-)

>   # cat current_clocksource 
>   MIPS 

> MIPS is the CP0 count register.  pit is the i8259 and jiffies simply counts
> interrupts like in the old days so has problems with lost timer interrupts
> and generally not such a great idea for tickless.  You should be able to
> switch between all these drivers by something like:

>   # echo jiffies > current_clocksource
>   Time: jiffies clocksource has been installed.
>   #

> Try switching between all the available clocksources a few times to see if
> that's working right also.

    It died after I selected jiffies.

>    Ralf

WBR, Sergei