Re: [PATCH v9 7/7] thermal/drivers/loongson2: Add Loongson-2K0300 support

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [Medium] thermal/drivers/loongson2: unmasked trip IRQ in
  ls2k0300_thermal_hw_init()
--

commit 024ebeb46fbe6ba2893fe68297ad030cb9ce5fe2
Author: Binbin Zhou <zhoubinbin@loongson.cn>

thermal/drivers/loongson2: Add Loongson-2K0300 support

This commit adds thermal sensor support for the Loongson-2K0300 SoC,
reading calibration data from the CHIP ID syscon registers and falling
back to an uncalibrated slope if the initial reading is out of range.

> diff --git a/drivers/thermal/loongson2_thermal.c b/drivers/thermal/loongson2_thermal.c
> index 4ce162dfb1229..68e6105051c60 100644
> --- a/drivers/thermal/loongson2_thermal.c
> +++ b/drivers/thermal/loongson2_thermal.c
[ ... ]
> @@ -87,6 +122,107 @@ static int loongson2_thermal_set_trips(struct thermal_zone_device *tz, int low,
[ ... ]
> +static int ls2k0300_thermal_hw_init(struct platform_device *pdev,
> +				    struct loongson2_thermal_data *data)
> +{
> +	struct device *dev = &pdev->dev;
> +	int ret;
> +
> +	data->regmap_cfg = syscon_regmap_lookup_by_phandle(dev->of_node, "loongson,chipid");
> +	if (IS_ERR(data->regmap_cfg))
> +		return PTR_ERR(data->regmap_cfg);
> +
> +	ret = ls2k0300_thermal_read_calib(data);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to read calibration data");
> +
> +	writel(LS2K0300_THSENS_INIT_MASK, data->ctrl_reg + LS2K0300_THSENS_CFG_REG);
> +
> +	/*
> +	 * Wait for the ADC to produce the first valid conversion before
> +	 * using OUT_REG for the old-fuse sanity check.
> +	 */
> +	usleep_range(1000, 2000);
> +
> +	ls2k0300_thermal_detect_old_fuse(dev, data);
> +
> +	return 0;
> +}
[ ... ]
> @@ -178,6 +314,10 @@ static int ls2k2000_thermal_hw_init(struct platform_device *pdev,
>  	return 0;
>  }
>  
> +static const struct thermal_zone_device_ops ls2k0300_thermal_zone_ops = {
> +	.get_temp = ls2k0300_thermal_get_temp,
> +};

[Severity: Medium]
Can this cause a thermal interrupt storm on Loongson-2K0300 if trip
interrupts were left enabled by firmware or a previous kernel across
kexec?

Unlike ls2k1000_thermal_hw_init() and ls2k2000_thermal_hw_init(),
ls2k0300_thermal_hw_init() does not clear LOONGSON2_THSENS_STATUS_REG or
disable trip-point interrupts, while loongson2_thermal_probe() still
unconditionally registers loongson2_thermal_irq_thread().  Because
ls2k0300_thermal_zone_ops omits .set_trips, thermal_zone_device_update()
in the IRQ handler cannot update the hardware trip window or mask the
interrupt enable bit, so the comparator will keep re-asserting the
level-triggered interrupt on subsequent ADC conversions.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/cover.1794211535.git.zhoubinbin@loongson.cn?part=7