Re: [PATCH 1/3] firmware: qcom_scm: Add support for tsens reinit workaround

[Bhupesh Sharma]

Hi Bjorn,

Thanks for your review.

On 7/19/22 8:28 AM, Bjorn Andersson wrote:
> On Fri 01 Jul 09:58 CDT 2022, Bhupesh Sharma wrote:
>
> Please update $subject to match the most uses prefix for the qcom_scm
> driver.
>
> > Some versions of QCoM tsens controller might enter a
>
> s/QCoM/Qualcomm/ please.

Ok.

> > 'bad state' while running stability tests causing sensor
> > temperatures/interrupts status to be in an 'invalid' state.
> >
> > It is recommended to re-initialize the tsens controller
> > via trustzone (secure registers) using scm call(s) when that
> > happens.
> >
> > Add support for the same in the qcom_scm driver.
> >
> > Cc: Amit Kucheria <amitk@xxxxxxxxxx>
> > Cc: Thara Gopinath <thara.gopinath@xxxxxxxxx>
> > Cc: linux-pm@xxxxxxxxxxxxxxx
> > Cc: linux-arm-msm@xxxxxxxxxxxxxxx
> > Signed-off-by: Bhupesh Sharma <bhupesh.sharma@xxxxxxxxxx>
> > ---
> >   drivers/firmware/qcom_scm.c | 17 +++++++++++++++++
> >   drivers/firmware/qcom_scm.h |  4 ++++
> >   include/linux/qcom_scm.h    |  2 ++
> >   3 files changed, 23 insertions(+)
> >
> > diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> > index 3163660fa8e2..0bc7cc466218 100644
> > --- a/drivers/firmware/qcom_scm.c
> > +++ b/drivers/firmware/qcom_scm.c
> > @@ -796,6 +796,23 @@ int qcom_scm_mem_protect_video_var(u32 cp_start, u32 cp_size,
> >   }
> >   EXPORT_SYMBOL(qcom_scm_mem_protect_video_var);
> >   
> > +int qcom_scm_tsens_reinit(int *tsens_ret)
> > +{
> > +	unsigned int ret;
>
> qcom_scm_call() returns negative numbers on error, so this should be
> signed.

Ok.

> > +	struct qcom_scm_desc desc = {
>
> const?

Sure.

> > +		.svc = QCOM_SCM_SVC_TSENS,
> > +		.cmd = QCOM_SCM_TSENS_INIT_ID,
> > +	};
> > +	struct qcom_scm_res res;
> > +
> > +	ret = qcom_scm_call(__scm->dev, &desc, &res);
> > +	if (tsens_ret)
> > +		*tsens_ret = res.result[0];
>
> Most similar qcom_scm functions use negative return value for errors and
> positive (including 0) values for the returned data.
>
> Looking at patch 3, the only thing you seem to care about is tsens_ret
> being 0 or not, so I do think you would be fine returning both using the
> return value.

Ok, let me double check the same and fix the same in v2.

Regards,
Bhupesh


> > +
> > +	return ret;
> > +}
> > +EXPORT_SYMBOL(qcom_scm_tsens_reinit);
> > +
> >   static int __qcom_scm_assign_mem(struct device *dev, phys_addr_t mem_region,
> >   				 size_t mem_sz, phys_addr_t src, size_t src_sz,
> >   				 phys_addr_t dest, size_t dest_sz)
> > diff --git a/drivers/firmware/qcom_scm.h b/drivers/firmware/qcom_scm.h
> > index 0d51eef2472f..495fa00230c7 100644
> > --- a/drivers/firmware/qcom_scm.h
> > +++ b/drivers/firmware/qcom_scm.h
> > @@ -94,6 +94,10 @@ extern int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc,
> >   #define QCOM_SCM_PIL_PAS_IS_SUPPORTED	0x07
> >   #define QCOM_SCM_PIL_PAS_MSS_RESET	0x0a
> >   
> > +/* TSENS Services and Function IDs */
> > +#define QCOM_SCM_SVC_TSENS		0x1E
> > +#define QCOM_SCM_TSENS_INIT_ID		0x5
> > +
> >   #define QCOM_SCM_SVC_IO			0x05
> >   #define QCOM_SCM_IO_READ		0x01
> >   #define QCOM_SCM_IO_WRITE		0x02
> > diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h
> > index f8335644a01a..f8c9eb739df1 100644
> > --- a/include/linux/qcom_scm.h
> > +++ b/include/linux/qcom_scm.h
> > @@ -124,4 +124,6 @@ extern int qcom_scm_lmh_dcvsh(u32 payload_fn, u32 payload_reg, u32 payload_val,
> >   extern int qcom_scm_lmh_profile_change(u32 profile_id);
> >   extern bool qcom_scm_lmh_dcvsh_available(void);
> >   
> > +extern int qcom_scm_tsens_reinit(int *tsens_ret);
> > +
> >   #endif
> > --
> > 2.35.3