[PATCH] ARM: dts: imx6qdl-hummingboard: Add PCIe support

[l.stach@pengutronix.de (Lucas Stach)]

Hi Jon,

Am Mittwoch, den 06.05.2015, 13:04 +0200 schrieb Jon Nettleton:
> On Wed, May 6, 2015 at 12:35 PM, Russell King - ARM Linux
> <linux@arm.linux.org.uk> wrote:
> >
> > On Mon, Apr 27, 2015 at 04:51:57PM +0800, Shawn Guo wrote:
> > > On Wed, Apr 08, 2015 at 09:41:53PM -0300, Fabio Estevam wrote:
> > > > From: Fabio Estevam <fabio.estevam@freescale.com>
> > > >
> > > > Add PCIe support. Based on a patch from Rabeeh Khoury from the solid-run
> > > > tree.
> > > >
> > > > Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> > >
> > > Russell,
> > >
> > > Are you fine with this patch?
> >
> > I don't have a view on this because I don't have any experience of PCIe.
> > However, I don't see anything obviously wrong with the patch.
> >
> 
> That patch is fine.  In the SolidRun kernel we are actually using
> 0x80000000 as our pin strength to accept the default value, but I have
> previously tested with 0x1b0b1 and it works as expected.
> 
> I have not tested this with the upstream kernel but previously MSI was
> not working properly on the iMX6 pcie implementation.  This was worked
> around by either disabling the kernel config option, or add pci=nomsi
> to the kernel commandline.  I currently have a patch that takes a
> nomsi device-tree option to workaround this bug.
> 
> Is pcie working with MSI now on the iMX6 hardware?
> 
> -Jon
> 

MSI is working properly on i.MX6 with all devices I had a chance to
test. If you've got some specific devices where it doesn't work with a
mainline kernel I would be interested in receiving bug reports.

It is certainly no hardware limitation, so please don't push a
workaround into DT.

Regards,
Lucas

-- 
Pengutronix e.K.             | Lucas Stach                 |
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