FSL MSI Mapping

FSL MSI Mapping

[Johannes Thumshirn]

Hi,

I got notified about your patch to support multiple MSI Vectors on Freescale
PowerPC platforms. Is there any reason why it wasn't applied until now? I
couldn't find anything about it in the list archives.

I think it would be a real benefit for all to have multiple MSI vecotrs on
PowerPCs.

Thanks in advance,
       Johannes

Re: FSL MSI Mapping

[Scott Wood]

On Tue, 2014-10-28 at 18:06 +0100, Johannes Thumshirn wrote:
> Hi,
> 
> I got notified about your patch to support multiple MSI Vectors on Freescale
> PowerPC platforms. Is there any reason why it wasn't applied until now? I
> couldn't find anything about it in the list archives.
> 
> I think it would be a real benefit for all to have multiple MSI vecotrs on
> PowerPCs.

Could you provide a patchwork link to the patch you're talking about?

-Scott

Re: FSL MSI Mapping

[Johannes Thumshirn]

On Tue, Oct 28, 2014 at 02:10:18PM -0500, Scott Wood wrote:
> On Tue, 2014-10-28 at 18:06 +0100, Johannes Thumshirn wrote:
> > Hi,
> >
> > I got notified about your patch to support multiple MSI Vectors on Freescale
> > PowerPC platforms. Is there any reason why it wasn't applied until now? I
> > couldn't find anything about it in the list archives.
> >
> > I think it would be a real benefit for all to have multiple MSI vecotrs on
> > PowerPCs.
>
> Could you provide a patchwork link to the patch you're talking about?

Unfortunately I couldn't find it in the ppc patchwork, but here are the links to
the patch series in the list archives:
https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-February/115484.html
https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-February/115485.html
https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-February/115486.html

Thanks,
	Johannes

Re: FSL MSI Mapping

[Scott Wood]

On Wed, 2014-10-29 at 07:54 +0100, Johannes Thumshirn wrote:
> On Tue, Oct 28, 2014 at 02:10:18PM -0500, Scott Wood wrote:
> > On Tue, 2014-10-28 at 18:06 +0100, Johannes Thumshirn wrote:
> > > Hi,
> > >
> > > I got notified about your patch to support multiple MSI Vectors on Freescale
> > > PowerPC platforms. Is there any reason why it wasn't applied until now? I
> > > couldn't find anything about it in the list archives.
> > >
> > > I think it would be a real benefit for all to have multiple MSI vecotrs on
> > > PowerPCs.
> >
> > Could you provide a patchwork link to the patch you're talking about?
> 
> Unfortunately I couldn't find it in the ppc patchwork, but here are the links to
> the patch series in the list archives:
> https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-February/115484.html
> https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-February/115485.html
> https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-February/115486.html

They were in patchwork with changes requested in patch 1/2:
http://patchwork.ozlabs.org/patch/322497/
http://patchwork.ozlabs.org/patch/322334/

-Scott

Re: FSL MSI Mapping

[Michael Ellerman]

On Tue, 2014-10-28 at 18:06 +0100, Johannes Thumshirn wrote:
> Hi,
> 
> I got notified about your patch to support multiple MSI Vectors on Freescale
> PowerPC platforms. Is there any reason why it wasn't applied until now? I
> couldn't find anything about it in the list archives.
> 
> I think it would be a real benefit for all to have multiple MSI vecotrs on
> PowerPCs.

Why would you not use MSI-X ?

cheers

Re: FSL MSI Mapping

[Johannes Thumshirn]

On Thu, Oct 30, 2014 at 02:51:57PM +1100, Michael Ellerman wrote:
> On Tue, 2014-10-28 at 18:06 +0100, Johannes Thumshirn wrote:
> > Hi,
> >
> > I got notified about your patch to support multiple MSI Vectors on Freescale
> > PowerPC platforms. Is there any reason why it wasn't applied until now? I
> > couldn't find anything about it in the list archives.
> >
> > I think it would be a real benefit for all to have multiple MSI vecotrs on
> > PowerPCs.
>
> Why would you not use MSI-X ?
>

Simply because our hardware only supports MSI.

Re: FSL MSI Mapping

[Johannes Thumshirn]

On Thu, Oct 30, 2014 at 02:51:57PM +1100, Michael Ellerman wrote:
> On Tue, 2014-10-28 at 18:06 +0100, Johannes Thumshirn wrote:
> > Hi,
> >
> > I got notified about your patch to support multiple MSI Vectors on Freescale
> > PowerPC platforms. Is there any reason why it wasn't applied until now? I
> > couldn't find anything about it in the list archives.
> >
> > I think it would be a real benefit for all to have multiple MSI vecotrs on
> > PowerPCs.
>
> Why would you not use MSI-X ?
>
> cheers
>
>

Does anyone (especially the original author) have any objections if I re-spin
the patch series?

Re: FSL MSI Mapping

[Sebastian Andrzej Siewior]

On 10/31/2014 09:12 AM, Johannes Thumshirn wrote:
> On Thu, Oct 30, 2014 at 02:51:57PM +1100, Michael Ellerman wrote:
>> Why would you not use MSI-X ?

If I'm not mistaken, a PCI-E requirement is to support MSI but MSI-X is
optional. And with MSI you can have multiple interrupts per single
device (power of two, max 32).
Now imagine you have a FPGA with two (or more) different devices in it
and you don't want them to share the IRQ line (for $reason). I bet the
HW developer sees MSI and MSI-X and the former is for some reason
cheaper compared to MSI-X and it fits the needs. So…

> 
> Does anyone (especially the original author) have any objections if I re-spin
> the patch series?

I didn't get around to address the review comments so it did not went
in and there was no v2. Feel free re-do the series.

Sebastian