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

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Submitter Thinh Nguyen
Date Feb. 5, 2019, 9:22 p.m.
Message ID <a28cfcee61f0842efe114c97b566bb3d967ba3d3.1549326366.git.thinhn@synopsys.com>
Download mbox | patch
Permalink /patch/719049/
State New
Headers show

Comments

Thinh Nguyen - Feb. 5, 2019, 9:22 p.m.
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.

Fixes: 03e6742584af ("PCI: Override Synopsys USB 3.x HAPS device class")
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
---
 drivers/pci/quirks.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
Bjorn Helgaas - Feb. 5, 2019, 11:31 p.m.
[+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.

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?

lspci also doesn't look at the Class Code when it looks up the text
name of devices, so it will print the same name for both.  Of course,
the Linux PCI ID database at https://pci-ids.ucw.cz/read/PC/16c3 shows
basically no information for the 0x16c3 Vendor ID, so it won't print
anything useful no matter what.  You could add some things there :)

> Fixes: 03e6742584af ("PCI: Override Synopsys USB 3.x HAPS device class")
> Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
> ---
>  drivers/pci/quirks.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index b0a413f3f7ca..e2a879e93d86 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -639,8 +639,9 @@ static void quirk_synopsys_haps(struct pci_dev *pdev)
>  		break;
>  	}
>  }
> -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SYNOPSYS, PCI_ANY_ID,
> -			 quirk_synopsys_haps);
> +DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_SYNOPSYS, PCI_ANY_ID,
> +			       PCI_CLASS_SERIAL_USB_XHCI, 0,
> +			       quirk_synopsys_haps);
>  
>  /*
>   * Let's make the southbridge information explicit instead of having to
> -- 
> 2.11.0
>
John Youn - Feb. 6, 2019, 1:01 a.m.
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
Bjorn Helgaas - Feb. 6, 2019, 1:55 a.m.
On Tue, Feb 05, 2019 at 05:01:18PM -0800, John Youn wrote:
> On 02/05/2019 03:32 PM, Bjorn Helgaas wrote:
> > 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.

If that's true, your vendor was very unlucky in choosing 0xabcd.  They
also have a pretty serious misunderstanding of how PCI IDs work, which
will cause you major headaches if they continue allocating Device IDs
from the Synopsys space.

In this particular case it's probably not a disaster because the
i.MX6QP and i.MX7D devices are both bridges (Root Ports, I think), and
we don't currently have any drivers that claim those by ID.  The
portdrv claims them by Class Code.

> > 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.

I think that'd be a good idea.  I think portdrv will claim the Root
Port first, before dwc3-haps has a chance, so the driver core won't
even call dwc3_haps_probe().

But if you unset CONFIG_PCIEPORTBUS or boot with "pcie_ports=compat",
I bet dwc3-haps *will* claim it, and things will fail a little less
gracefully.

Bjorn
Lucas Stach - Feb. 6, 2019, 9:27 a.m.
Hi Bjorn,

Am Dienstag, den 05.02.2019, 17:31 -0600 schrieb Bjorn Helgaas:
> [+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)

The first incorporation of this IP in a Freescale SoC (i.MX6Q) also
uses the device ID 0xabcd.

So this seems to be a major miscommunication between NXP/Freescale and
Synopsys.

Regards,
Lucas

>   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.
> 
> 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?
> 
> lspci also doesn't look at the Class Code when it looks up the text
> name of devices, so it will print the same name for both.  Of course,
> the Linux PCI ID database at https://pci-ids.ucw.cz/read/PC/16c3
> shows
> basically no information for the 0x16c3 Vendor ID, so it won't print
> anything useful no matter what.  You could add some things there :)
> 
> > Fixes: 03e6742584af ("PCI: Override Synopsys USB 3.x HAPS device
> > class")
> > Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
> > ---
> >  drivers/pci/quirks.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> > index b0a413f3f7ca..e2a879e93d86 100644
> > --- a/drivers/pci/quirks.c
> > +++ b/drivers/pci/quirks.c
> > @@ -639,8 +639,9 @@ static void quirk_synopsys_haps(struct pci_dev
> > *pdev)
> >  		break;
> >  	}
> >  }
> > -DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SYNOPSYS, PCI_ANY_ID,
> > -			 quirk_synopsys_haps);
> > +DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_SYNOPSYS, PCI_ANY_ID,
> > +			       PCI_CLASS_SERIAL_USB_XHCI, 0,
> > +			       quirk_synopsys_haps);
> >  
> >  /*
> >   * Let's make the southbridge information explicit instead of
> > having to
> > -- 
> > 2.11.0
> >

Patch

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index b0a413f3f7ca..e2a879e93d86 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -639,8 +639,9 @@  static void quirk_synopsys_haps(struct pci_dev *pdev)
 		break;
 	}
 }
-DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SYNOPSYS, PCI_ANY_ID,
-			 quirk_synopsys_haps);
+DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_SYNOPSYS, PCI_ANY_ID,
+			       PCI_CLASS_SERIAL_USB_XHCI, 0,
+			       quirk_synopsys_haps);
 
 /*
  * Let's make the southbridge information explicit instead of having to