Re: [PATCH 0/4 V3] irqchip: gic: Introduce ARM GICv2m MSI(-X) support

[Mark Rutland <mark.rutland@arm.com>]

On Thu, Jul 17, 2014 at 03:48:29PM +0100, Suravee Suthikulanit wrote:
> On 7/17/2014 8:55 AM, Mark Rutland wrote:
> > Hi Jason,
> >
> > On Thu, Jul 17, 2014 at 02:18:54PM +0100, Jason Cooper wrote:
> >> On Wed, Jul 09, 2014 at 06:05:00PM -0500, suravee.suthikulpanit@amd.com wrote:
> >>> From: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
> >>>
> >>> This patch set introduces support for MSI(-X) in GICv2m specification,
> >>> which is implemented in some variation of GIC400.
> >>>
> >>> This depends on and has been tested with the V7 of"Add support for PCI in AArch64"
> >>> (https://lkml.org/lkml/2014/3/14/320).
> >>>
> >>> Changes in V3:
> >>>      * Rebase to git://git.infradead.org/users/jcooper/linux.git irqchip/gic
> >>>        (per Jason Cooper request)
> >>>      * Misc fix/clean up per Mark Rutland comments
> >>>      * Minor Clean up in the driver/irqchip/irq-gic-v2m.c: alloc_msi_irqs()
> >>>      * Patch 4 is new to the series:
> >>>          * Add ARM64-specific version arch_setup_msi_irqs() to allow support
> >>>            for Multiple MSI.
> >>>          * Add support for Multiple MSI for GICv2m.
> >>>
> >>> Suravee Suthikulpanit (4):
> >>>    irqchip: gic: Add binding probe for ARM GIC400
> >>>    irqchip: gic: Restructuring ARM GIC code
> >>>    irqchip: gic: Add supports for ARM GICv2m MSI(-X)
> >>>    irqchip: gicv2m: Add support for multiple MSI for ARM64 GICv2m
> >>
> >> Ok, patch #1 applied to irqchip/urgent.  Patches 2 and 3 applied to
> >> irqchip/gic with irqchip/urgent merged in.  To facilitate
> >> testing/merging, I've prepared an unsigned tag for you on the
> >> irqchip/gic branch:
> >
> > I'm a little concerned that this is all going through for v3.17 without
> > a {Reviewed,Acked}-by from Marc or anyone working with GIC{,v2m}.
> 
> > While his comments on v1 have been addressed, he has not had a chance to
> > acknowledge the solutions. I appreciate Marc's holiday is unfortunately
> > timed.
> >
> > I also have an open concern with the binding with regard to the
> > orthogonality of GICV GICH and the MSI registers.
> 
> The MSI part is normally enabled from the optional "msi-controller" 
> keyword. It should not really matter which compatible ID it uses.

I meant the fact that the MSI registers being described in reg[4],
rather than how the driver determines MSI support.

> Ooops. I noticed that was accidentally dropped the check for 
> "msi-controller" in the gicv2m_of_init() function.  I'll send a follow 
> up patch to fix this.

Sure. Whatever happens we should have both the msi-controller property
and the registers for the MSI block before we enable MSI support.

> > Suravee, do you need this urgently for v3.17? I was under the impression
> > that we wouldn't have full PCIe support by then.
> >
> 
> PCI is the dependency for this patch to function.  So, it should be 
> aligned with upstreaming of PCI patches.

Ok, so it sounds like this can wait for the moment (but we should
definitely ensure this gets some testing before then).

Cheers,
Mark