linux-kernel - Re: [PATCH v3 3/7] iio: pressure: bmp280: Remove config error check for IIR filter updates

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Zsjf0bVLZyPqBxru@smile.fi.intel.com>
Date: Fri, 23 Aug 2024 22:15:29 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Vasileios Amoiridis <vassilisamir@...il.com>
Cc: jic23@...nel.org, lars@...afoo.de, robh@...nel.org, krzk+dt@...nel.org,
	conor+dt@...nel.org, ang.iglesiasg@...il.com,
	linus.walleij@...aro.org, biju.das.jz@...renesas.com,
	javier.carrasco.cruz@...il.com, semen.protsenko@...aro.org,
	579lpy@...il.com, ak@...klinger.de, linux-iio@...r.kernel.org,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 3/7] iio: pressure: bmp280: Remove config error check
 for IIR filter updates

On Fri, Aug 23, 2024 at 08:17:10PM +0200, Vasileios Amoiridis wrote:
> When there is a change in the configuration of the BMP3xx device, several
> steps take place. These steps include:
> 
> 1) Update the OSR settings and check if there was an update
> 2) Update the ODR settings and check if there was an update
> 3) Update the IIR settings and check if there was an update
> 4) Check if there was an update with the following procedure:
> 	a) Set sensor to SLEEP mode and after to NORMAL mode to trigger
> 	   a new measurement.
> 	b) Wait the maximum amount possible depending on the OSR settings
> 	c) Check the configuration error register if there was an error
> 	   during the configuration of the sensor.
> 
> This check is necessary, because there could be a case where the OSR is
> too high for the requested ODR so either the ODR needs to be slower or the
> OSR needs to be less. This is something that is checked internally by the
> sensor when it runs in NORMAL mode.
> 
> In the BMP58x devices the previous steps are done internally by the sensor.
> 
> The IIR filter settings do not depend on the OSR or ODR settings, and there
> is no need to run a check in case they change.

...

> +	ret = regmap_update_bits(data->regmap, BMP580_REG_DSP_IIR,
> +				 BMP580_DSP_IIR_PRESS_MASK |
> +				 BMP580_DSP_IIR_TEMP_MASK, reg_val);

Better to split on logical bounds

	ret = regmap_update_bits(data->regmap, BMP580_REG_DSP_IIR,
				 BMP580_DSP_IIR_PRESS_MASK | BMP580_DSP_IIR_TEMP_MASK,
				 reg_val);

-- 
With Best Regards,
Andy Shevchenko