linux-kernel - Re: [PATCH v4 5/7] drivers: thermal: tsens: Add watchdog support

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Date:   Mon, 3 Feb 2020 10:42:13 -0800
From:   Bjorn Andersson <bjorn.andersson@...aro.org>
To:     Amit Kucheria <amit.kucheria@...aro.org>
Cc:     linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        swboyd@...omium.org, sivaa@...eaurora.org,
        Andy Gross <agross@...nel.org>,
        Amit Kucheria <amit.kucheria@...durent.com>,
        linux-pm@...r.kernel.org
Subject: Re: [PATCH v4 5/7] drivers: thermal: tsens: Add watchdog support

On Thu 30 Jan 05:27 PST 2020, Amit Kucheria wrote:

> TSENS IP v2.3 onwards adds support for a watchdog to detect if the TSENS
> HW FSM is stuck. Add support to detect and restart the FSM in the
> driver. The watchdog is configured by the bootloader, we just enable the
> watchdog bark as a debug feature in the kernel.
> 
> Signed-off-by: Amit Kucheria <amit.kucheria@...aro.org>
> ---
>  drivers/thermal/qcom/tsens-common.c | 43 +++++++++++++++++++++++++++++
>  drivers/thermal/qcom/tsens-v2.c     | 10 +++++++
>  drivers/thermal/qcom/tsens.h        | 14 ++++++++++
>  3 files changed, 67 insertions(+)
> 
> diff --git a/drivers/thermal/qcom/tsens-common.c b/drivers/thermal/qcom/tsens-common.c
> index 9d1594d2f1ed..ee2414f33606 100644
> --- a/drivers/thermal/qcom/tsens-common.c
> +++ b/drivers/thermal/qcom/tsens-common.c
> @@ -377,6 +377,26 @@ irqreturn_t tsens_critical_irq_thread(int irq, void *data)
>  	struct tsens_irq_data d;
>  	unsigned long flags;
>  	int temp, ret, i;
> +	u32 wdog_status, wdog_count;
> +
> +	if (priv->feat->has_watchdog) {
> +		ret = regmap_field_read(priv->rf[WDOG_BARK_STATUS], &wdog_status);
> +		if (ret)
> +			return ret;
> +
> +		if (wdog_status) {
> +			/* Clear WDOG interrupt */
> +			regmap_field_write(priv->rf[WDOG_BARK_CLEAR], 1);
> +			regmap_field_write(priv->rf[WDOG_BARK_CLEAR], 0);
> +			ret = regmap_field_read(priv->rf[WDOG_BARK_COUNT], &wdog_count);
> +			if (ret)
> +				return ret;
> +			if (wdog_count)
> +				dev_dbg(priv->dev, "%s: watchdog count: %d\n", __func__, wdog_count);
> +
> +			return IRQ_HANDLED;

Patch looks good, but would is make sense to fall through and handle
critical interrupts as well (both in positive and error cases of this
hunk)?


Reviewed-by: Bjorn Andersson <bjorn.andersson@...aro.org>

Regards,
Bjorn