On Mon, 2023-11-27 at 15:09 +0800, Macpaul Lin wrote:
> On 11/25/23 18:37, Krzysztof Kozlowski and Chunfeng Yun wrote:
> >
> >
> > External email : Please do not click links or open attachments
> > until you
> > have verified the sender or the content.
> >
> > On 25/11/2023 02:23, Chunfeng Yun wrote:
> > > Due to some old SoCs with shared t-phy only support force-mode
> > > switch, and
> > > can't use compatible to distinguish between shared and non-shared
> > > t-phy,
> > > add a property to supported it.
> > > But now prefer to use "mediatek,syscon-type" on new SoC as far as
> > > possible.
> > >
> > > Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
> > > ---
> > > Documentation/devicetree/bindings/phy/mediatek,tphy.yaml | 6
> > > ++++++
> > > 1 file changed, 6 insertions(+)
> > >
> > > diff --git
> > > a/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml
> > > b/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml
> > > index 2bb91542e984..eedba5b7025e 100644
> > > --- a/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml
> > > +++ b/Documentation/devicetree/bindings/phy/mediatek,tphy.yaml
> > > @@ -235,6 +235,12 @@ patternProperties:
> > > Specify the flag to enable BC1.2 if support it
> > > type: boolean
> > >
> > > + mediatek,force-mode:
> > > + description:
> > > + Use force mode to switch shared phy mode, perfer to
> > > use the bellow
> >
> > I still do not understand what is the "force mode" you want to use.
> > What
> > modes do you have? What are the characteristics of force mode?
> >
> > Also, please run spellcheck.
> >
> > Best regards,
> > Krzysztof
> >
>
> Thanks!
>
> 1. I've tested this patch and it could solve the clock unstable for
> XHCI1 on mt8195 or mt8395 during system boot up or during
> unload/reload the phy driver.
>
> The error message has been listed as follows.
>
> [ 13.849936][ T72] xhci-mtk 11290000.usb: supply vbus not found,
> using dummy regulator
> [ 13.851300][ T72] xhci-mtk 11290000.usb: uwk - reg:0x400,
> version:104
> [ 13.852624][ T72] xhci-mtk 11290000.usb: xHCI Host Controller
> [ 13.853393][ T72] xhci-mtk 11290000.usb: new USB bus
> registered,
> assigned bus number 3
> [ 13.874490][ T72] xhci-mtk 11290000.usb: clocks are not stable
> (0x3d0f)
> [ 13.875369][ T72] xhci-mtk 11290000.usb: can't setup: -110
> [ 13.876091][ T72] xhci-mtk 11290000.usb: USB bus 3 deregistered
> [ 13.877081][ T72] xhci-mtk: probe of 11290000.usb failed with
> error
> -110
>
> 2. This is a fix patch to XHCI1 since MT8195 has been upstream.
> Please add "Fixes:" tags and "Cc: stable@xxxxxxxxxx" to back ward
> porting to previous stable trees.
>
> For example, add
> Fixes: 6b5ef194611e5 ("phy: mediatek: tphy: remove macros to prepare
> bitfield")
> is suggested since the force-mode was missing in the previous
> implementation which causes hardware function was abnormal.
> However, add
> Fixes: 33d18746fa514 ("phy: phy-mtk-tphy: use new io helpers to
> access
> register")
> will be better since the USB support for mt8195 is already enabled
> in
> late 2021.
It don't take into account this case, it assume that only use the
default mode (PCIe).
>
> 3. How about we revise the description as follows for more precisely?
>
> mediatek,force-mode:
> description:
> The force mode is used to manually switch the shared PHY mode
> between USB and PCIe. When force-mode is set, the USB 3.0 mode
> will be selected.
seems not right, the mode/type is selected by the phy consumer.
> This is typically required for older SoCs
> that do not automatically manage PHY mode switching.
> For newer SoCs that support it, it is preferable to use the
> "mediatek,syscon-type" property instead.
> type: boolean
>
> Thanks,
> Macpaul Lin
