Re: [PATCH RESEND] PCI: Check for USB xHCI class for HAPS platform

[John Youn <john.youn@synopsys.com>]

On 02/05/2019 03:32 PM, Bjorn Helgaas wrote:
> [+cc Richard, Lucas]
> 
> On Tue, Feb 05, 2019 at 01:04:28PM -0800, Thinh Nguyen wrote:
>> The Synopsys HAPS USB controller has a VID PID (16c3,abcd) that matches
>> to an existing PCIe controller. This quirk is intended for USB HAPS
>> devices only. To fix this, check for the PCI class USB xHCI to prevent
>> matching the PCIe controllers.
> 
> So there are at least three different parts with the same Vendor &
> Device ID ([16c3:abcd]):
> 
>    1) Synopsys HAPS USB3 controller
>    2) Synopsys PCIe IP in the NXP i.MX6QP (reported by Lukas)
>    3) Synopsys PCIe IP in the NXP i.MX7D (reported by Trent)
> 
> I don't know if Synopsys is to blame for 2 & 3, or if NXP was expected
> to change the Vendor ID when incorporating the Synopsys IP into the
> i.MX designs.  But even leaving the default Device ID of the PCIe IP
> the same as another Synopsys device was probably a bad idea.


Hi Bjorn,

 From talking with our PCIe folks, our best guess is a vendor
misconfiguration. The PCIe IP ships with a different PID by default
and does not collide with USB.

> dwc3-haps claims by Vendor & Device ID; it doesn't look at the Class
> Code.  What happens when it tries to claim the PCIe IP in i.MX?

We can add the class code to dwc3-haps to account for this.

John