Re: IRQ behaivour has been changed from v4.14 to v4.15-rc1

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

On Thu, 2017-12-28 at 18:21 +0100, Thomas Gleixner wrote:
> On Thu, 28 Dec 2017, Shevchenko, Andriy wrote:
> 
> > Hi!
> > 
> > Experimenting with AtomISP (yes, code is ugly and MSI handling
> > rather
> > hackish, though...).
> > 
> > So, with v4.14 base:
> > 
> > [   33.639224] atomisp-isp2 0000:00:03.0: Start stream on pad 1 for
> > asd0
> > [   33.652355] atomisp-isp2 0000:00:03.0: irq:0x20
> > [   33.662456] atomisp-isp2 0000:00:03.0: irq:0x20
> > [   33.698064] atomisp-isp2 0000:00:03.0: stream[0] started.
> > 
> > Ctrl+C
> > 
> > [   48.185643] atomisp-isp2 0000:00:03.0: <atomisp_dqbuf: -512
> > [   48.204641] atomisp-isp2 0000:00:03.0: release device ATOMISP ISP
> > CAPTURE output
> > ...
> > 
> > and machine still alive.
> > 
> > 
> > With v4.15-rc1 base (basically your branch + some my hack patches)
> > the
> > IR
> > Q behaviour changed, i.e. I have got:
> > 
> > 
> > [   85.167061] spurious APIC interrupt through vector ff on CPU#0,
> > should never happen.
> > [   85.199886] atomisp-isp2 0000:00:03.0: stream[0] started.
> > 
> > and Ctrl+C does NOT work. Machine just hangs.
> > 
> > It might be related to this:
> > https://lkml.org/lkml/2017/12/22/697
> 
> I don't think so.
> 
> Does the patch below cure it?

Unfortunately, no.

Same behaviour.

Tell me if I need to provide some debug before it hangs. For now I have
apic=debug (AFAIR it doesn't affect this).

> 
> Thanks,
> 
> 	tglx
> 8<-----------------
>  arch/x86/kernel/apic/apic_flat_64.c   |    2 +-
>  arch/x86/kernel/apic/probe_32.c       |    2 +-
>  arch/x86/kernel/apic/x2apic_cluster.c |    2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> --- a/arch/x86/kernel/apic/apic_flat_64.c
> +++ b/arch/x86/kernel/apic/apic_flat_64.c
> @@ -151,7 +151,7 @@ static struct apic apic_flat __ro_after_
>  	.apic_id_valid			=
> default_apic_id_valid,
>  	.apic_id_registered		= flat_apic_id_registered,
>  
> -	.irq_delivery_mode		= dest_LowestPrio,
> +	.irq_delivery_mode		= dest_Fixed,
>  	.irq_dest_mode			= 1, /* logical */
>  
>  	.disable_esr			= 0,
> --- a/arch/x86/kernel/apic/probe_32.c
> +++ b/arch/x86/kernel/apic/probe_32.c
> @@ -105,7 +105,7 @@ static struct apic apic_default __ro_aft
>  	.apic_id_valid			=
> default_apic_id_valid,
>  	.apic_id_registered		=
> default_apic_id_registered,
>  
> -	.irq_delivery_mode		= dest_LowestPrio,
> +	.irq_delivery_mode		= dest_Fixed,
>  	/* logical delivery broadcast to all CPUs: */
>  	.irq_dest_mode			= 1,
>  
> --- a/arch/x86/kernel/apic/x2apic_cluster.c
> +++ b/arch/x86/kernel/apic/x2apic_cluster.c
> @@ -184,7 +184,7 @@ static struct apic apic_x2apic_cluster _
>  	.apic_id_valid			= x2apic_apic_id_valid,
>  	.apic_id_registered		=
> x2apic_apic_id_registered,
>  
> -	.irq_delivery_mode		= dest_LowestPrio,
> +	.irq_delivery_mode		= dest_Fixed,
>  	.irq_dest_mode			= 1, /* logical */
>  
>  	.disable_esr			= 0,
> 
> 

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy