Re: [PATCH v4 5/5] usb: host: add xhci-exynos driver

Jung Daehwan
2022-04-28T01:31:28Z

[-- Attachment #1: Type: text/plain, Size: 3264 bytes --]

On Tue, Apr 26, 2022 at 02:59:57PM +0200, Krzysztof Kozlowski wrote:
> On 26/04/2022 11:18, Daehwan Jung wrote:
> > This driver is for Samsung Exynos xhci host conroller. It uses xhci-plat
> > driver mainly and extends some functions by xhci hooks and overrides.
> >
> > It supports USB Audio offload with Co-processor. It only cares DCBAA,
> > Device Context, Transfer Ring, Event Ring, and ERST. They are allocated
> > on specific address with xhci hooks. Co-processor could use them directly
> > without xhci driver after then.
>
> This does not look like developed in current Linux kernel, but something
> out-of-tree, with some other unknown modifications. This is not how the
> code should be developed. Please rebase on linux-next and drop any
> unrelated modifications (these which are not sent with this patchset).
>

I've been developing on linux-next and I rebase before submitting.
Could you tell me one of dropped modifications or patches?

> (...)
>
> > +
> > +static int xhci_exynos_suspend(struct device *dev)
> > +{
> > + struct usb_hcd *hcd = dev_get_drvdata(dev);
> > + struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> > +
> > + /* TODO: AP sleep scenario*/
>
> Shall the patchset be called RFC?
>
OK. I will add RFC for this patch on next submission.

> > +
> > + return xhci_suspend(xhci, device_may_wakeup(dev));
> > +}
> > +
> > +static int xhci_exynos_resume(struct device *dev)
> > +{
> > + struct usb_hcd *hcd = dev_get_drvdata(dev);
> > + struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> > + int ret;
> > +
> > + /* TODO: AP resume scenario*/
> > +
> > + ret = xhci_resume(xhci, 0);
> > + if (ret)
> > + return ret;
> > +
> > + pm_runtime_disable(dev);
> > + pm_runtime_set_active(dev);
> > + pm_runtime_enable(dev);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct dev_pm_ops xhci_exynos_pm_ops = {
> > + SET_SYSTEM_SLEEP_PM_OPS(xhci_exynos_suspend, xhci_exynos_resume)
> > +};
> > +
> > +MODULE_DESCRIPTION("xHCI Exynos Host Controller Driver");
> > +MODULE_LICENSE("GPL");
>
> You don't have list of compatibles (and missing bindings), driver
> definition, driver registration. Entire solution is not used - nothing
> calls xhci_exynos_vendor_init(), because nothign uses "ops".
>

xhci_exynos_vendor_init is called in xhci-plat.c (xhci_vendor_init)
[v4,2/5] usb: host: add xhci hooks for xhci-exynos
ops are used in some files(xhci-mem.c, xhci.c ..) and the body of ops is in
all xhci-exynos.

xhci-exynos is not a standalone driver. It could be enabled when other module
makes xhci platform driver probed as it uses xhci platform mainly.
I thought I just used existing compltible not adding new one.
I will add them if needed.

> This does not work and it makes it impossible to test it. Please provide
> proper XHCI Exynos driver, assuming you need it and it is not part of
> regular Exynos XHCI drivers (DWC3 and so on).
>

What makes you think it doesn't work? I think it's almost proper. I just removed
other IPs code like Co-Processor(we call it abox) or Power Management because
it would make build-error. I've added hooking points in some files(xhci-mem.c,
xhci.c..) and ops are implemented in xhci-exynos. It's mainly operated with
xhci platform driver.

Best Regards,
Jung Daehwan

> Best regards,
> Krzysztof
>

[-- Attachment #2: Type: text/plain, Size: 0 bytes --]