powerpc/xics: Properly set Edge/Level type and enable resend

[Michael Ellerman]

On Tue, 2016-02-08 at 02:39:43 UTC, Benjamin Herrenschmidt wrote:
> This sets the type of the interrupt appropriately. We set it as follow:
> 
>  - If not mapped from the device-tree, we use edge. This is the case
> of the virtual interrupts and PCI MSIs for example.
> 
>  - If mapped from the device-tree and #interrupt-cells is 2 (PAPR
> compliant), we use the second cell to set the appropriate type
> 
>  - If mapped from the device-tree and #interrupt-cells is 1 (current
> OPAL on P8 does that), we assume level sensitive since those are
> typically going to be the PSI LSIs which are level sensitive.
> 
> Additionally, we mark the interrupts requested via the opal_interrupts
> property all level. This is a bit fishy but the best we can do until we
> fix OPAL to properly expose them with a complete descriptor. It is also
> correct for the current HW anyway as OPAL interrupts are currently PCI
> error and PSI interrupts which are level.
> 
> Finally now that edge interrupts are properly identified, we can enable
> CONFIG_HARDIRQS_SW_RESEND which will make the core re-send them if
> they occur while masked, which some drivers rely upon.
> 
> This fixes issues with lost interrupts on some Mellanox adapters.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/880a3d6afd068682d6386a0528

cheers