linux-kernel - Re: [PATCH 2/3] iio: imu: mpu6050: add level shifter flag

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: <FR3P281MB17575CB2EC8CFD3D5D74EC0CCEFCA@FR3P281MB1757.DEUP281.PROD.OUTLOOK.COM>
Date:   Mon, 25 Sep 2023 11:14:16 +0000
From:   Jean-Baptiste Maneyrol <Jean-Baptiste.Maneyrol@....com>
To:     Andy Shevchenko <andy.shevchenko@...il.com>,
        Andreas Kemnade <andreas@...nade.info>
CC:     "jic23@...nel.org" <jic23@...nel.org>,
        "lars@...afoo.de" <lars@...afoo.de>,
        "robh+dt@...nel.org" <robh+dt@...nel.org>,
        "krzysztof.kozlowski+dt@...aro.org" 
        <krzysztof.kozlowski+dt@...aro.org>,
        "conor+dt@...nel.org" <conor+dt@...nel.org>,
        "bcousson@...libre.com" <bcousson@...libre.com>,
        "tony@...mide.com" <tony@...mide.com>,
        "chenhuiz@...s.com" <chenhuiz@...s.com>,
        "linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-omap@...r.kernel.org" <linux-omap@...r.kernel.org>
Subject: Re: [PATCH 2/3] iio: imu: mpu6050: add level shifter flag

Hello,

these are very old unsupported chips, thus this is not something I can easily find. Even after doing some archaeology.

But when looking at register maps, it should only be used with MPU-9150 and not MPU-9250. I would feel much more comfortable to restrict this fix to MPU-9150 only (by testing chip_type against INV_MPU9150).

Thanks,
JB

From: Andy Shevchenko <andy.shevchenko@...il.com>
Sent: Monday, September 25, 2023 13:07
To: Andreas Kemnade <andreas@...nade.info>
Cc: jic23@...nel.org <jic23@...nel.org>; lars@...afoo.de <lars@...afoo.de>; robh+dt@...nel.org <robh+dt@...nel.org>; krzysztof.kozlowski+dt@...aro.org <krzysztof.kozlowski+dt@...aro.org>; conor+dt@...nel.org <conor+dt@...nel.org>; bcousson@...libre.com <bcousson@...libre.com>; tony@...mide.com <tony@...mide.com>; Jean-Baptiste Maneyrol <Jean-Baptiste.Maneyrol@....com>; chenhuiz@...s.com <chenhuiz@...s.com>; linux-iio@...r.kernel.org <linux-iio@...r.kernel.org>; devicetree@...r.kernel.org <devicetree@...r.kernel.org>; linux-kernel@...r.kernel.org <linux-kernel@...r.kernel.org>; linux-omap@...r.kernel.org <linux-omap@...r.kernel.org>
Subject: Re: [PATCH 2/3] iio: imu: mpu6050: add level shifter flag 
 
On Mon, Sep 25, 2023 at 1: 26 AM Andreas Kemnade <andreas@ kemnade. info> wrote: > > Some boards fail in magnetometer probe if flag is not set. Which flag? Can you elaborate a bit more? Does it deserve the Fixes tag? .. . > unsigned 
ZjQcmQRYFpfptBannerStart
This Message Is From an Untrusted Sender 
You have not previously corresponded with this sender. 
 
ZjQcmQRYFpfptBannerEnd
On Mon, Sep 25, 2023 at 1:26 AM Andreas Kemnade <andreas@...nade.info> wrote:
>
> Some boards fail in magnetometer probe if flag is not set.

Which flag? Can you elaborate a bit more?

Does it deserve the Fixes tag?

...

>         unsigned int val;
>         int ret;

> +       ret = regmap_update_bits(st->map, 0x1, 0x80,
> +                                st->level_shifter ? 0x80 : 0);

This is a bit cryptic, what does 1 stand for?

Also

  unsigned int mask = BIT(7);
  ...
  val = st->level_shifter ? mask : 0;

> +       if (ret)
> +               return ret;

...
> +       st->level_shifter = device_property_present(dev,
> +                                                   "invensense,level-shifter");

It was a recommendation to use _read_bool() when reading the value,
while the result will be the same.

--
With Best Regards,
Andy Shevchenko