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    SubjectRe: [RESEND PATCH 1/3] usb: dwc3: Don't reinitialize core during host bus-suspend/resume
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    Hi,


    On 1/10/2018 6:18 PM, Roger Quadros wrote:
    > Hi Manu,
    >
    > On 27/09/17 14:19, Manu Gautam wrote:
    >> Driver powers-off PHYs and reinitializes DWC3 core and gadget on
    >> resume. While this works fine for gadget mode but in host
    >> mode there is not re-initialization of host stack. Also, resetting
    >> bus as part of bus_suspend/resume is not correct which could affect
    >> (or disconnect) connected devices.
    >> Fix this by not reinitializing core on suspend/resume in host mode
    >> for HOST only and OTG/drd configurations.
    >>
    > All this seems correct but we (TI) were relying on dwc3_core_exit() to be called
    > during dwc3_suspend() to have the lowest power state for our platforms.
    >
    > After this patch, DWC3 controller and PHYs won't be turned off thus
    > preventing our platform from reaching low power levels.
    >
    > So this is a regression for us (TI) in v4.15-rc.
    >
    > Felipe, do you agree?
    >
    > If yes I can send a patch which fixes the regression
    > and also makes USB host work after suspend/resume.
    >

    I think it will be better to separate runtime_suspend and pm_suspend handling for
    host mode in dwc3. Powering offf/on PHYs and dwc3_core_exit/init across system
    suspend-resume should be ok but doing that for runtime suspend-resume is not
    correct.
    Let me know if that sounds ok, I can provide a patch for same instead of
    reverting this which affects runtime PM with dwc3 host.
    Also, we need to consider dwc3 in Host mode with dr_mode as DRD/OTG similar to
    dr_mode as HOST.


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    The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
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