Hi Rob. > -----Original Message----- > From: Rob Herring <robh@xxxxxxxxxx> > Sent: Friday, October 30, 2020 10:56 PM > To: Wan Mohamad, Wan Ahmad Zainie > <wan.ahmad.zainie.wan.mohamad@xxxxxxxxx> > Cc: bhelgaas@xxxxxxxxxx; lorenzo.pieralisi@xxxxxxx; linux- > pci@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > andriy.shevchenko@xxxxxxxxxxxxxxx; mgross@xxxxxxxxxxxxxxx; Raja > Subramanian, Lakshmi Bai <lakshmi.bai.raja.subramanian@xxxxxxxxx> > Subject: Re: [PATCH 1/2] dt-bindings: PCI: Add Intel Keem Bay PCIe controller > > On Fri, Oct 30, 2020 at 8:05 AM Wan Mohamad, Wan Ahmad Zainie > <wan.ahmad.zainie.wan.mohamad@xxxxxxxxx> wrote: > > > > Hi Rob. > > > > Thanks for the review. > > > > > -----Original Message----- > > > From: Rob Herring <robh@xxxxxxxxxx> > > > Sent: Wednesday, October 28, 2020 10:42 PM > > > To: Wan Mohamad, Wan Ahmad Zainie > > > <wan.ahmad.zainie.wan.mohamad@xxxxxxxxx> > > > Cc: bhelgaas@xxxxxxxxxx; lorenzo.pieralisi@xxxxxxx; linux- > > > pci@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > > > andriy.shevchenko@xxxxxxxxxxxxxxx; mgross@xxxxxxxxxxxxxxx; Raja > > > Subramanian, Lakshmi Bai <lakshmi.bai.raja.subramanian@xxxxxxxxx> > > > Subject: Re: [PATCH 1/2] dt-bindings: PCI: Add Intel Keem Bay PCIe > > > controller > > > > > > On Tue, Oct 27, 2020 at 02:00:10PM +0800, Wan Ahmad Zainie wrote: ... > > > > + num-viewport: > > > > + description: Number of view ports configured in hardware. > > > > + $ref: /schemas/types.yaml#/definitions/uint32 > > > > + default: 2 > > > > > > Pretty sure it's not 2 if num-ib-windows and num-ob-windows are 4. > > > > As per pcie-designware-host.c, default value is 2, if it is not set. > > Yes, that's true. > > > My example and the DT in my system is 4. > > I will fix in v2, by using const: 4. > > Should I drop default? > > Yes. > > BTW, I'm going to make all 3 properties obsolete. I'm working on a patch to > detect all this. It's pretty straight-forward, just see how many registers are > writable. The WIP patch is on my for-kernelci branch. I will take note on this. I also take a look into for-kernelci branch. I will spend some time to try it out with my patch. > > The problem with these properties is they are defined as RC and EP specific, > but they are really fixed h/w config independent of the mode. And num- > viewport is incomplete because the inbound and outbound sizes are > independent. The driver just currently doesn't use inbound windows for RC > mode. Also, the driver claims there can be up to 256 windows, but I'm not > really sure that's right. There's 2 platforms upstream (ls1088a and ls208xa) > claiming 256 windows in DT, but testing with the detection code indicates > they only have 16 IB and 16 OB windows. Perhaps if you have the DWC > manual you could confirm what's possible. Unfortunately, I don't have details on DWC manual. As for Keem Bay, from the information in its databook, it is synthesized with 8 IB and 8 OB windows. The values that I used for DT is based on recommendation from our boot firmware team. > > Rob Best regards, Zainie
