RE: [PATCH v6 8/8] usb: ehci-exynos: Change to use phy provided bythe generic phy framework

From: Alan Stern
Date: Wed Feb 05 2014 - 14:56:34 EST

On Wed, 5 Feb 2014, Kamil Debski wrote:

> Hi Alan,
> Thank you for your review.

You're welcome.

> >
> > > Change the phy provider used from the old one using the USB phy
> > You have removed all the OTG stuff from the driver. This wasn't
> > mentioned in the patch description, and it has no connection with the
> > PHY work.
> Maybe I'll explain more about what are we trying to achieve. The goal
> is to replace the old phy driver with the new one. In the old driver it was
> difficult to add support to new SoC. It also had issues with having device
> and
> host working together.
> You're right that until the old phy driver is removed support for the it
> should
> remain. To be able to remove the old driver both new USB2 and new USB3 phy
> drivers
> have to be ready. The USB3 driver is written by Vivek Gautam and as I see
> it, he
> is also close to completion.
> Regarding the otg part. The old phy driver is the only provider of the otg
> structure. It sets the host field of the structure. It is then used by
> samsung_usb2phy_init (drivers/usb/phy/phy-samsung-usb2.c) to check which
> driver is requesting the phy (is it host or device). In the new driver this
> is determined by the entry in device tree. So no need to check the otg
> struct
> and strstr (!) to check if dev_name is ehci, ohci or other, like the old
> driver.

Okay, that's fine. But please explain this in the patch description
next time. Otherwise the connection between the phy driver and the otg
structure is not at all clear; they look like two unrelated things.

Alan Stern

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