Hello,
Thanks for the patch!
On Wed, 16 Jan 2019 11:10:51 +0100, Paul Kocialkowski wrote:
> According to the chipidea driver bindings, the USB PHY is specified via
> the "phys" phandle node. However, this only takes effect for USB PHYs
> that use the common PHY framework. For legacy USB PHYs, a simple lookup
> based on the USB PHY type is done instead.
>
> This does not play out well when more than USB PHY is registered, since
"more than *one*"
> the first registered PHY matching the type will always be returned
> regardless of what the driver was bound to.
>
> Fix this by looking up the PHY based on the "phys" phandle node.
> Although generic PHYS and rather matched by their "phys-name"
I'm confused by "Although generic PHYS and rather matched". Perhaps
s/and/are/ ?
Also PHYS -> PHYs
> and not
> the "phys" phandle directly, there is no helper for similar lookup on
> legacy PHYs and it's probably not worth the effort to add it.
>
> When no legacy USB PHY is found by phandle, fallback to grabbing any
> registered USB2 PHY. This ensures backward compatibility if some users
> were actually relying on this mechanism.
>
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>
> ---
> drivers/usb/chipidea/core.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
> index 7bfcbb23c2a4..11d3ee1e3fe5 100644
> --- a/drivers/usb/chipidea/core.c
> +++ b/drivers/usb/chipidea/core.c
> @@ -954,8 +954,14 @@ static int ci_hdrc_probe(struct platform_device *pdev)
> } else if (ci->platdata->usb_phy) {
> ci->usb_phy = ci->platdata->usb_phy;
> } else {
> + ci->usb_phy = devm_usb_get_phy_by_phandle(dev->parent, "phys",
> + 0);
> ci->phy = devm_phy_get(dev->parent, "usb-phy");
> - ci->usb_phy = devm_usb_get_phy(dev->parent, USB_PHY_TYPE_USB2);
I'm not sure why you change the order of legacy PHY lookup vs. generic
PHY lookup.
> +
> + /* Fallback to grabbing any registered USB2 PHY */
> + if (IS_ERR(ci->phy) && IS_ERR(ci->usb_phy))
> + ci->usb_phy = devm_usb_get_phy(dev->parent,
> + USB_PHY_TYPE_USB2);
Why is this conditional on the generic PHY lookup failing?
Don't we simply want:
ci->phy = devm_phy_get(dev->parent, "usb-phy");
ci->usb_phy = devm_usb_get_phy_by_phandle(dev->parent, "phys", 0);
if (IS_ERR(ci->usb_phy))
ci->usb_phy = devm_usb_get_phy(dev->parent, USB_PHY_TYPE_USB2);
?
Does this needs a "Fixes:" tag ? It's not fixing a regression because
nobody complained until now, but it's really fixing a behavior that
wasn't correct.
Best regards,
Thomas
--
Thomas Petazzoni, CTO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
