Re: [PATCH v5 4/6] usb: xhci: use bus->sysdev for DMA configuration

[Mathias Nyman]

On 12.01.2017 10:38, Roger Quadros wrote:
> Mathias,
>
> On 11/01/17 17:08, Alan Stern wrote:
> > On Wed, 11 Jan 2017, Mathias Nyman wrote:
> >
> > > On 17.11.2016 13:43, Sriram Dash wrote:
> > > > From: Arnd Bergmann <arnd@xxxxxxxx>
> > > >
> > > > For xhci-hcd platform device, all the DMA parameters are not
> > > > configured properly, notably dma ops for dwc3 devices. So, set
> > > > the dma for xhci from sysdev. sysdev is pointing to device that
> > > > is known to the system firmware or hardware.
> > > >
> > > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > > > Signed-off-by: Sriram Dash <sriram.dash@xxxxxxx>
> > > > Tested-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
> > > > ---
> > >
> > > ...
> > >
> > > > +	/*
> > > > +	 * sysdev must point to a device that is known to the system firmware
> > > > +	 * or PCI hardware. We handle these three cases here:
> > > > +	 * 1. xhci_plat comes from firmware
> > > > +	 * 2. xhci_plat is child of a device from firmware (dwc3-plat)
> > > > +	 * 3. xhci_plat is grandchild of a pci device (dwc3-pci)
> > > > +	 */
> > > > +	sysdev = &pdev->dev;
> > > > +	if (sysdev->parent && !sysdev->of_node && sysdev->parent->of_node)
> > > > +		sysdev = sysdev->parent;
> > > > +#ifdef CONFIG_PCI
> > > > +	else if (sysdev->parent && sysdev->parent->parent &&
> > > > +		 sysdev->parent->parent->bus == &pci_bus_type)
> > > > +		sysdev = sysdev->parent->parent;
> > > > +#endif
> > > > +
> > >
> > > Not maybe the the ideal situation here, and looks really tailored to make PCI dwc3
> > > controllers with xhci support work.
> > >
> > > Was there some reason child devices can't automatically inherit the dma mask from the parents,
> > > forcing us to dig it from grandparents?
> > >
> > > Anyway, looks like the dwc3 part is already in 4.10-rc,
> > > If Greg and Alan want to take this series that's fine by me
> >
> > I have no objections.
> >
> > Alan Stern
> >
> > > I haven't tested that it won't break anything on PCI XHCI controllers though
> > >
> > > -Mathias
>
> Are you going to pick all the remaining patches from this series (i.e. 1 to 4)?
>
> That should fix the warning that people are seeing on v4.10-rc.

Let's check with Greg

Greg, 5/6 and 6/6 are in 4.10-rc already, causing additional warnings for
people using dwc3 xhci.

First 3 patches change usb core,  patch 4 xhci.

Compiles and boots, doesn't break pci xhci (non-dwc3) functionality

Would you like me to send first 4 patches for usb-linus to get a clean final 4.10
without warnings, or to send them for usb-next?

Or will you just pick the patches from here directly.

for patch 4/6:
Acked-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>

-Mathias