Re: [RFC PATCH v2 1/3] dt-bindings: usb: mtk-xhci: add compatible for mt8195

From: Chunfeng Yun
Date: Sat Feb 06 2021 - 21:14:13 EST


On Wed, 2021-02-03 at 11:31 +0100, Greg Kroah-Hartman wrote:
> On Wed, Feb 03, 2021 at 06:26:40PM +0800, Chunfeng Yun wrote:
> > There are 4 USB controllers on MT8195, the controllers (IP1~IP3,
> > exclude IP0) have a wrong default SOF/ITP interval which is
> > calculated from the frame counter clock 24Mhz by default, but
> > in fact, the frame counter clock is 48Mhz, so we should set
> > the accurate interval according to 48Mhz. Here add a new compatible
> > for MT8195, it's also supported in driver. But the first controller
> > (IP0) has no such issue, we prefer to use generic compatible,
> > e.g. mt8192's compatible.
> >
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> > ---
> > v2: no changes
>
> Note, I do not apply patches with "RFC" as obviously you do not think
> they are worthy of being applied. I don't see what you are asking to be
> done with this set of patches, please explain?
The DTS patch [2/3] in the series will cause merge conflict, due to the
dependent patches are not upstreamed.

Another problem is that I wander to know whether the compatible usage as
following is allowed:

arch/arm64/boot/dts/mediatek/mt8195.dtsi

usb@11200000 { // ip0
compatible = "mediatek,mt8192-xhci", // here use mt8192's
compatible, avoid changing SOF/ITP interval for ip0, because it's
default value is ok."mediatek,mt8192-xhci" is not supported in driver,
so finally will use generic copatible "mediatek,mtk-xhci".

"mediatek,mtk-xhci";
....
};

usb@11290000 { // ip1
compatible = "mediatek,mt8195-xhci", // here use mt8195's
compatible, used to change SOF/ITP interval, due the the wrong default
value.
"mediatek,mtk-xhci";
};

usb@112a0000 { // ip2
compatible = "mediatek,mt8195-xhci", // same as ip1
"mediatek,mtk-xhci";
};

Thank you

>
> thanks,
>
> greg k-h