Messages in this thread | | | Date | Thu, 20 Dec 2012 09:51:53 -0800 | Subject | Re: [PATCH v5 3/4] USB: ehci-s5p: Add phy driver support | From | Doug Anderson <> |
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On Wed, Dec 19, 2012 at 10:37 PM, Vivek Gautam <gautamvivek1987@gmail.com> wrote: > > On Thu, Dec 20, 2012 at 5:00 AM, Doug Anderson <dianders@chromium.org> wrote: >> >> On Tue, Dec 18, 2012 at 6:43 AM, Vivek Gautam <gautam.vivek@samsung.com> wrote: >>> +static void s5p_ehci_phy_enable(struct s5p_ehci_hcd *s5p_ehci) >>> +{ >>> + struct platform_device *pdev = to_platform_device(s5p_ehci->dev); >>> + >>> + if (s5p_ehci->phy) { >>> + samsung_usbphy_set_type(s5p_ehci->phy, USB_PHY_TYPE_HOST); >> >> This confuses me. Why are you setting the type to host here? >> > Being in host controller, before calling usb_phy_init() we set type to > Host since, with certain SOCs > like 4210, same register has different bit settings for HOST type and > device type. So setting this > to Host type here make the flow of usb_phy_init to go in the direction of Host.
OK. I think I need to study the code more...
>>> >>> + phy = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2); >>> + if (IS_ERR_OR_NULL(phy)) { >>> + /* Fallback to pdata */ >>> + if (!pdata) { >>> + dev_err(&pdev->dev, "no platform data or transceiver defined\n"); >>> + return -EPROBE_DEFER; >> >> Shouldn't you return -EINVAL like the old code did? > > We are deferring the probe since the usb-phy transceiver may get > probed after ehci/ohci controllers. > And if we return -EINVAL like the previous code, we would end up not > setting the phy.
OK. Something is wrong here then, since this really isn't an error: * It should be commented about why you're deferring. * You shouldn't have a dev_err for something that's not fatal.
Ideally we'd want something that would force probing to happen in the right order. I spent a little time looking and didn't see anything, but maybe I'm missing something obvious. If nothing pops out, the defer seems OK as long as it is commented well.
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