RE: [External] : [PATCH v2 1/2] dmaengine: dw-edma: Add AMD MDB Endpoint Support

[Verma, Devendra]

[AMD Official Use Only - AMD Internal Distribution Only]

> -----Original Message-----
> From: Bjorn Helgaas <helgaas@xxxxxxxxxx>
> Sent: Tuesday, September 16, 2025 20:36
> To: ALOK TIWARI <alok.a.tiwari@xxxxxxxxxx>
> Cc: Verma, Devendra <Devendra.Verma@xxxxxxx>; bhelgaas@xxxxxxxxxx;
> mani@xxxxxxxxxx; vkoul@xxxxxxxxxx; dmaengine@xxxxxxxxxxxxxxx; linux-
> pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Simek, Michal
> <michal.simek@xxxxxxx>
> Subject: Re: [External] : [PATCH v2 1/2] dmaengine: dw-edma: Add AMD MDB
> Endpoint Support
>
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>
> On Tue, Sep 16, 2025 at 04:25:49PM +0530, ALOK TIWARI wrote:
> >
> >
> > On 9/16/2025 4:13 PM, Devendra K Verma wrote:
> > > +   /*
> > > +    * Synopsys and AMD (Xilinx) use the same VSEC ID for the purpose
> > > +    * of map, channel counts, etc.
> > > +    */
> > > +   if (vendor != PCI_VENDOR_ID_SYNOPSYS ||
> > > +       vendor != PCI_VENDOR_ID_XILINX)
> > > +           return;
> >
> > if, vendor == PCI_VENDOR_ID_XILINX condition will true
> >
> > should not be if (vendor != PCI_VENDOR_ID_SYNOPSYS && vendor !=
> > PCI_VENDOR_ID_XILINX) ?
>
> Good catch, I mistakenly said this part was correct, but you're right; it's obviously
> broken.
>
> The alternate structure I suggested would avoid this problem.
>
> > > +
> > > +   cap = DW_PCIE_VSEC_DMA_ID;
> > > +   if (vendor == PCI_VENDOR_ID_XILINX)
> > > +           cap = DW_PCIE_XILINX_MDB_VSEC_ID;
> > > +
> > > +   vsec = pci_find_vsec_capability(pdev, vendor, cap);
> > >     if (!vsec)
> >
> >
> > Thanks,
> > Alok

Thanks for noticing it, this was quickly corrected and updated in v3 of the same patch.

Regards,
Devendra