Re: [PATCH v5 3/3] pci:aer: add support aer interrupt with none MSI/MSI-X/INTx mode

From: Rob Herring <robh@kernel.org>
To: Po Liu <po.liu@nxp.com>
Cc: Shawn Guo <shawnguo@kernel.org>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	Roy Zang <roy.zang@nxp.com>, Arnd Bergmann <arnd@arndb.de>,
	Marc Zyngier <marc.zyngier@arm.com>,
	Stuart Yoder <stuart.yoder@nxp.com>, Leo Li <leoyang.li@nxp.com>,
	"M.H. Lian" <minghuan.lian@nxp.com>,
	Murali Karicheri <m-karicheri2@ti.com>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Mingkai Hu <mingkai.hu@nxp.com>
Subject: Re: [PATCH v5 3/3] pci:aer: add support aer interrupt with none MSI/MSI-X/INTx mode
Date: Fri, 23 Sep 2016 08:06:20 -0500	[thread overview]
Message-ID: <20160923130620.GA1486@rob-hp-laptop> (raw)
In-Reply-To: <VI1PR0401MB1709F91B0C1EB6C80D741E4492F50@VI1PR0401MB1709.eurprd04.prod.outlook.com>

On Sun, Sep 18, 2016 at 03:37:27AM +0000, Po Liu wrote:
> Hi Shawn,
> 
> 
> >  -----Original Message-----
> >  From: Shawn Guo [mailto:shawnguo@kernel.org]
> >  Sent: Sunday, September 18, 2016 8:52 AM
> >  To: Po Liu
> >  Cc: linux-pci@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
> >  linux-kernel@vger.kernel.org; devicetree@vger.kernel.org; Roy Zang; Arnd
> >  Bergmann; Marc Zyngier; Stuart Yoder; Leo Li; M.H. Lian; Murali
> >  Karicheri; Bjorn Helgaas; Mingkai Hu
> >  Subject: Re: [PATCH v5 3/3] pci:aer: add support aer interrupt with none
> >  MSI/MSI-X/INTx mode
> >  
> >  On Tue, Sep 13, 2016 at 12:40:59PM +0800, Po Liu wrote:
> >  > On some platforms, root port doesn't support MSI/MSI-X/INTx in RC mode.
> >  > When chip support the aer interrupt with none MSI/MSI-X/INTx mode,
> >  > maybe there is interrupt line for aer pme etc. Search the interrupt
> >  > number in the fdt file. Then fixup the dev->irq with it.
> >  >
> >  > Signed-off-by: Po Liu <po.liu@nxp.com>
> >  
> >  Will the new kernel work with existing/old DTB?  I'm trying to
> >  understand the dependency between driver and DTS changes.
> 
> Yes, We've never use name 'intr' before. So we remove it is ok. 
> 'aer' is a dts name for researching it's true interrupt number by 
> kernel. This patch is first time to use name 'aer'. So it must be 
> compatible with existing/old DTB.

Please explain why you are not breaking compatibility in the commit 
message. I asked for this on v2.

> >  > ---
> >  > changes for v5:
> >  > 	- Add clear 'aer' interrup-names description
> >  >
> >  >  .../devicetree/bindings/pci/layerscape-pci.txt     | 11 +++++---
> >  >  drivers/pci/pcie/portdrv_core.c                    | 31
> >  +++++++++++++++++++---
> >  >  2 files changed, 35 insertions(+), 7 deletions(-)
> >  >
> >  > diff --git a/Documentation/devicetree/bindings/pci/layerscape-pci.txt
> >  > b/Documentation/devicetree/bindings/pci/layerscape-pci.txt
> >  > index 41e9f55..101d0a7 100644
> >  > --- a/Documentation/devicetree/bindings/pci/layerscape-pci.txt
> >  > +++ b/Documentation/devicetree/bindings/pci/layerscape-pci.txt
> >  > @@ -18,8 +18,10 @@ Required properties:
> >  >  - reg: base addresses and lengths of the PCIe controller
> >  >  - interrupts: A list of interrupt outputs of the controller. Must
> >  contain an
> >  >    entry for each entry in the interrupt-names property.
> >  > -- interrupt-names: Must include the following entries:
> >  > -  "intr": The interrupt that is asserted for controller interrupts
> >  > +- interrupt-names: It may be include the following entries:

"may be" is not okay. It should be "must" or explain when an interrupt 
would not be present. Really, differences in interrupts means you need 
different compatible strings.

Rob

> >  > +  "aer": The interrupt that is asserted for aer interrupt
> >  > +  "pme": The interrupt that is asserted for pme interrupt
> >  > +  ......