Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH RESEND] PCI: Check for USB xHCI class for HAPS platform
To:     Bjorn Helgaas <helgaas@kernel.org>,
        Thinh Nguyen <thinh.nguyen@synopsys.com>
CC:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
        "Lukas F. Hartmann" <lukas@mntmn.com>,
        Trent Piepho <tpiepho@impinj.com>,
        John Youn <john.youn@synopsys.com>,
        Richard Zhu <hongxing.zhu@nxp.com>,
        Lucas Stach <l.stach@pengutronix.de>
References: <a28cfcee61f0842efe114c97b566bb3d967ba3d3.1549326366.git.thinhn@synopsys.com>
 <20190205233159.GC7268@google.com>
From:   John Youn <john.youn@synopsys.com>
Message-ID: <5d78ac08-0809-d219-ff7c-5cea5f7aba8b@synopsys.com>
Date:   Tue, 5 Feb 2019 17:01:18 -0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.7.0
MIME-Version: 1.0
In-Reply-To: <20190205233159.GC7268@google.com>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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