Messages in this thread | | | Date | Tue, 17 Oct 2023 18:22:06 +0200 | Subject | Re: [PATCH] arm64: dts: qcom: sc8280xp-x13s: Use the correct DP PHY compatible | From | Konrad Dybcio <> |
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On 10/17/23 05:28, Bjorn Andersson wrote: > On Mon, Oct 16, 2023 at 12:10:18PM +0300, Dmitry Baryshkov wrote: >> On Mon, 16 Oct 2023 at 12:01, Johan Hovold <johan@kernel.org> wrote: >>> >>> On Mon, Oct 16, 2023 at 11:51:33AM +0300, Dmitry Baryshkov wrote: >>>> On Fri, 29 Sept 2023 at 19:03, Konrad Dybcio <konrad.dybcio@linaro.org> wrote: >>>>> >>>>> The DP PHY needs different settings when an eDP display is used. >>>>> Make sure these apply on the X13s. >>>> >>>> Could you please clarify, is it the same PHY type, just being >>>> repurposed for eDP or is it a different PHY type? >>> >>> Same PHY, just different settings AFAIK. >>> >>>> If the former is the case (and the same PHY can be used for both DP >>>> and eDP), it should carry the same compatible string and use software >>>> mechanisms (e.g. phy_set_mode_ext()) to be programmed for the correct >>>> operation mode. >>> >>> Possibly, but that's not how the current binding and implementation >>> works: >>> >>> 6993c079cd58 ("dt-bindings: phy: qcom-edp: Add SC8280XP PHY compatibles") >>> 2300d1cb24b3 ("phy: qcom: edp: Introduce support for DisplayPort") >>> 3b7267dec445 ("phy: qcom: edp: Add SC8280XP eDP and DP PHYs") >>> >>> https://lore.kernel.org/lkml/20220810040745.3582985-1-bjorn.andersson@linaro.org/ >>> >>> And you'd still need to infer the mode from DT somehow. >> >> If it is the same hardware block, it seems incorrect to have two >> different compat entries. For example, for PCIe RC vs PCIe EP we >> specify the PHY mode from the host controller driver. >> I'd say, we need to fix the bindings for both DP/eDP controller and >> the PHY. See the `phy-mode` DT property for example. >> > > It is one hardware block, supporting both eDP and DP, so I like your > suggestion of having a single compatible instead and using some other > means of defining the configuration. I just wasn't able to find a > better way to do so back when I wrote the binding/driver... Since this one is still unused, we can deprecate it (not sure if remove, but deprecate) and add phy-type instead. I was quite surprised to see that a new compatible was added as well :/
Konrad
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