RE: [PATCH] thermal: imx: Fix race condition in imx_thermal_probe()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



> -----Original Message-----
> From: Fabio Estevam [mailto:festevam@xxxxxxxxx]
> Sent: Saturday, February 3, 2018 2:18 AM
> To: rui.zhang@xxxxxxxxx
> Cc: edubezval@xxxxxxxxx; mikhail.lappo@xxxxxxxxxxx; linux-
> pm@xxxxxxxxxxxxxxx; dl-linux-imx <linux-imx@xxxxxxx>;
> p.zabel@xxxxxxxxxxxxxx; shawnguo@xxxxxxxxxx; stable@xxxxxxxxxxxxxxx;
> Fabio Estevam <fabio.estevam@xxxxxxx>
> Subject: [PATCH] thermal: imx: Fix race condition in imx_thermal_probe()
> 
> From: Mikhail Lappo <mikhail.lappo@xxxxxxxxxxx>
> 
> When device boots with T > T_trip_1 and requests interrupt, the race
> condition takes place. The interrupt comes before
> THERMAL_DEVICE_ENABLED is set. This leads to an attempt to reading
> sensor value from irq and disabling the sensor, based on the data->mode
> field, which expected to be THERMAL_DEVICE_ENABLED, but still stays as
> THERMAL_DEVICE_DISABLED. Afher this issue sensor is never re-enabled, as
> the driver state is wrong.
> 
> Fix this problem by setting the 'data' members prior to requesting the
> interrupts.
> 
> Fixes: 37713a1e8e4c ("thermal: imx: implement thermal alarm interrupt
> handling")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Mikhail Lappo <mikhail.lappo@xxxxxxxxxxx>
> Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxx>

Looks reasonable to me.
Acked-by: Dong Aisheng <aisheng.dong@xxxxxxx>

Regards
Dong Aisheng

> ---
>  drivers/thermal/imx_thermal.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
> index a67781b..ee3a215 100644
> --- a/drivers/thermal/imx_thermal.c
> +++ b/drivers/thermal/imx_thermal.c
> @@ -637,6 +637,9 @@ static int imx_thermal_probe(struct platform_device
> *pdev)
>  	regmap_write(map, TEMPSENSE0 + REG_CLR,
> TEMPSENSE0_POWER_DOWN);
>  	regmap_write(map, TEMPSENSE0 + REG_SET,
> TEMPSENSE0_MEASURE_TEMP);
> 
> +	data->irq_enabled = true;
> +	data->mode = THERMAL_DEVICE_ENABLED;
> +
>  	ret = devm_request_threaded_irq(&pdev->dev, data->irq,
>  			imx_thermal_alarm_irq,
> imx_thermal_alarm_irq_thread,
>  			0, "imx_thermal", data);
> @@ -649,9 +652,6 @@ static int imx_thermal_probe(struct platform_device
> *pdev)
>  		return ret;
>  	}
> 
> -	data->irq_enabled = true;
> -	data->mode = THERMAL_DEVICE_ENABLED;
> -
>  	return 0;
>  }
> 
> --
> 2.7.4





[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]