Re: [PATCH v3 04/10] usb: dwc3: use quirks to know if a particualr platform doesn't have PHY

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Hi,

On Thursday 05 December 2013 01:28 PM, Heikki Krogerus wrote:
Hi,

On Thu, Dec 05, 2013 at 12:04:46PM +0530, Kishon Vijay Abraham I wrote:
On Wednesday 04 December 2013 08:10 PM, Heikki Krogerus wrote:
On Mon, Nov 25, 2013 at 03:31:24PM +0530, Kishon Vijay Abraham I wrote:
There can be systems which does not have an external phy, so get
phy only if no quirks are added that indicates the PHY is not present.
Introduced two quirk flags to indicate the *absence* of usb2 phy and
usb3 phy. Also remove checking if return value is -ENXIO since it's now
changed to always enable usb_phy layer.

Can you guys explain why is something like this needed? Like with
clocks and gpios, the device drivers shouldn't need to care any more
if the platform has the phys or not. -ENODEV tells you your platform

Shouldn't we report if a particular platform needs a PHY and not able to get
it. How will a user know if a particular controller is not working because it's
not able to get and initialize the PHYs? Don't you think in such cases it's
better to fail (and return from probe) because the controller will not work
anyway without the PHY?

My point is that you do not need to separately tell this to the driver
like you do with the quirks (if you did, then you would need to fix
your framework and not hack the drivers).

Like I said, ENODEV tells you that there is no phy on this platform
for you, allowing you to safely continue. If your phy driver is not
loaded, the framework already returns EPROBE_DEFER, right. Any other

right. but that doesn't consider broken dt data. With quirks we'll able to tell if a controller in a particular platform has PHY or not without depending on the dt data.
error when getting the phy you can consider critical. They are the
errors telling you that you do need a phy on this platform, but
something actually went wrong when getting it.
Not on all scenarios though :-s

Thanks
Kishon
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