linux-kernel - Re: [RESEND,PATCH 1/2] firmware: qcom: scm: Add SDI disable support

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Date:   Fri, 19 May 2023 13:16:56 +0200
From:   Robert Marko <robimarko@...il.com>
To:     Mukesh Ojha <quic_mojha@...cinc.com>
Cc:     agross@...nel.org, andersson@...nel.org, konrad.dybcio@...aro.org,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        srichara@...cinc.com
Subject: Re: [RESEND,PATCH 1/2] firmware: qcom: scm: Add SDI disable support

On Thu, 18 May 2023 at 16:25, Mukesh Ojha <quic_mojha@...cinc.com> wrote:
>
>
>
> On 5/18/2023 7:32 PM, Robert Marko wrote:
> > Some SoC-s like IPQ5018 require SDI(Secure Debug Image) to be disabled
> > before trying to reboot, otherwise board will just hang after reboot has
> > been issued via PSCI.
> >
> > So, provide a call to SCM that allows disabling it.
> >
> > Signed-off-by: Robert Marko <robimarko@...il.com>
>
> This scm call support indeed needed for reboot cases, but i am not sure
> about target specific check in the later patch.

I am not really sure where to put it, maybe as part of qcom_scm_shutdown?
Yesterday I found out that in OpenWrt we also have a Google IPQ4019 board that
has been needing SDI to be disabled as well.

Regards,
Robert
>
> Acked-by: Mukesh Ojha <quic_mojha@...cinc.com>
>
> -- Mukesh
>
> > ---
> >   drivers/firmware/qcom_scm.c | 23 +++++++++++++++++++++++
> >   drivers/firmware/qcom_scm.h |  1 +
> >   2 files changed, 24 insertions(+)
> >
> > diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> > index fde33acd46b7..bdc9324d4e62 100644
> > --- a/drivers/firmware/qcom_scm.c
> > +++ b/drivers/firmware/qcom_scm.c
> > @@ -407,6 +407,29 @@ int qcom_scm_set_remote_state(u32 state, u32 id)
> >   }
> >   EXPORT_SYMBOL(qcom_scm_set_remote_state);
> >
> > +static int qcom_scm_disable_sdi(void)
> > +{
> > +     int ret;
> > +     struct qcom_scm_desc desc = {
> > +             .svc = QCOM_SCM_SVC_BOOT,
> > +             .cmd = QCOM_SCM_BOOT_SDI_CONFIG,
> > +             .args[0] = 1, /* Disable watchdog debug */
> > +             .args[1] = 0, /* Disable SDI */
> > +             .arginfo = QCOM_SCM_ARGS(2),
> > +             .owner = ARM_SMCCC_OWNER_SIP,
> > +     };
> > +     struct qcom_scm_res res;
> > +
> > +     ret = qcom_scm_clk_enable();
> > +     if (ret)
> > +             return ret;
> > +     ret = qcom_scm_call(__scm->dev, &desc, &res);
> > +
> > +     qcom_scm_clk_disable();
> > +
> > +     return ret ? : res.result[0];
> > +}
> > +
> >   static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
> >   {
> >       struct qcom_scm_desc desc = {
> > diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
> > index e6e512bd57d1..7b68fa820495 100644
> > --- a/drivers/firmware/qcom_scm.h
> > +++ b/drivers/firmware/qcom_scm.h
> > @@ -80,6 +80,7 @@ extern int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc,
> >   #define QCOM_SCM_SVC_BOOT           0x01
> >   #define QCOM_SCM_BOOT_SET_ADDR              0x01
> >   #define QCOM_SCM_BOOT_TERMINATE_PC  0x02
> > +#define QCOM_SCM_BOOT_SDI_CONFIG     0x09
> >   #define QCOM_SCM_BOOT_SET_DLOAD_MODE        0x10
> >   #define QCOM_SCM_BOOT_SET_ADDR_MC   0x11
> >   #define QCOM_SCM_BOOT_SET_REMOTE_STATE      0x0a