linux-kernel - Re: [PATCH v2 5/5] thermal: qcom: tsens: Add reinit quirk support for sm6375 controller

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Date:   Thu, 28 Jul 2022 16:12:27 +0200
From:   Konrad Dybcio <konrad.dybcio@...ainline.org>
To:     Bhupesh Sharma <bhupesh.sharma@...aro.org>,
        linux-pm@...r.kernel.org
Cc:     bhupesh.linux@...il.com, linux-kernel@...r.kernel.org,
        bjorn.andersson@...aro.org, linux-arm-msm@...r.kernel.org,
        daniel.lezcano@...aro.org, robh+dt@...nel.org, rafael@...nel.org,
        Amit Kucheria <amitk@...nel.org>,
        Thara Gopinath <thara.gopinath@...il.com>
Subject: Re: [PATCH v2 5/5] thermal: qcom: tsens: Add reinit quirk support for
 sm6375 controller



On 24.07.2022 14:24, Bhupesh Sharma wrote:
> tsens controller(s) on Qualcomm sm6375 SoC might start in
> an unknown state or start with TSENS_EN indicating
> a 'disabled' state when they enter linux world.
> 
> In such cases, it is useful to try and reinit them via
> trustzone [via scm call(s)], at the very start.
> 
> Add hooks for the same in the qcom tsens driver.
> 
> Cc: Bjorn Andersson <bjorn.andersson@...aro.org>
> Cc: Amit Kucheria <amitk@...nel.org>
> Cc: Thara Gopinath <thara.gopinath@...il.com>
> Cc: linux-pm@...r.kernel.org
> Cc: linux-arm-msm@...r.kernel.org
> Signed-off-by: Bhupesh Sharma <bhupesh.sharma@...aro.org>
> ---
This sadly doesn't work.. the issue on 6375 is that the controller
is in some weird state at boot and this bit that's higher up:

        ret = regmap_field_read(priv->rf[TSENS_EN], &enabled);
        if (ret)
                goto err_put_device;
        if (!enabled) {
                dev_err(dev, "%s: device not enabled\n", __func__);
                ret = -ENODEV;
                goto err_put_device;
        }

does not succeed.

Moving the code added in the patch up or calling
qcom_scm_tsens_reinit() or qcom_scm_tsens_reinit() and 
tsens_reenable_hw_after_scm(priv) directly before this enable
check also fails. In fact, the latter crashes the platform..

I don't want to block this series, so I suggest the 6375 part can
be dropped for now.

Konrad