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    SubjectRE: [PATCH 0/3] (Qualcomm) UFS device reset support
    Date
    > 
    > On Wed 05 Jun 02:32 PDT 2019, Avri Altman wrote:
    >
    > > >
    > > > On Tue 04 Jun 22:50 PDT 2019, Avri Altman wrote:
    > > >
    > > > > Hi,
    > > > >
    > > > > >
    > > > > > On Tue, Jun 4, 2019 at 12:22 AM Bjorn Andersson
    > > > > > <bjorn.andersson@linaro.org> wrote:
    > > > > > >
    > > > > > > This series exposes the ufs_reset line as a gpio, adds support for ufshcd
    > to
    > > > > > > acquire and toggle this and then adds this to SDM845 MTP.
    > > > > > >
    > > > > > > Bjorn Andersson (3):
    > > > > > > pinctrl: qcom: sdm845: Expose ufs_reset as gpio
    > > > > > > scsi: ufs: Allow resetting the UFS device
    > > > > > > arm64: dts: qcom: sdm845-mtp: Specify UFS device-reset GPIO
    > > > > >
    > > > > > Adding similar change as in sdm845-mtp to the not yet upstream
    > > > > > blueline dts, I validated this allows my micron UFS pixel3 to boot.
    > > > > >
    > > > > > Tested-by: John Stultz <john.stultz@linaro.org>
    > > > > Maybe ufs_hba_variant_ops would be the proper place to add this?
    > > > >
    > > >
    > > > Are you saying that these memories only need a reset when they are
    > > > paired with the Qualcomm host controller?
    > > ufs_hba_variant_ops is for vendors to implement their own vops,
    > > and as you can see, many of them do.
    > > Adding hw_reset to that template seems like the proper way
    > > to do what you are doing.
    > >
    >
    > Right, but the vops is operations related to the UFS controller, this
    > property relates to the memory connected.
    This is not entirely accurate. Those are vendor/board specific,
    As the original commit log indicates:
    " vendor/board specific and hence determined with
    the help of compatible property in device tree."

    I would rather have this new vop:
    void (*device_reset)(struct ufs_hba *), Or whatever,
    actively set in ufs_hba_variant_ops, rather than ufshcd_init_device_reset
    failing as part of the default init flow.

    Thanks,
    Avri

    >
    > E.g I have a Hynix memory and John have a Micron memory that needs this
    > reset and my assumption is that these memories will need their RESET pin
    > toggled regardless of which controller they are connected to.
    >
    > Regards,
    > Bjorn

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