linux-kernel - Re: [PATCH v2 4/5] ARM: dts: imx6sx: Use nvmem-cells for tempmon

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20171018022943.GF18810@dragon>
Date:   Wed, 18 Oct 2017 10:29:45 +0800
From:   Shawn Guo <shawnguo@...nel.org>
To:     Leonard Crestez <leonard.crestez@....com>
Cc:     Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Zhang Rui <rui.zhang@...el.com>,
        Eduardo Valentin <edubezval@...il.com>,
        Mark Rutland <mark.rutland@....com>,
        Lothar Waßmann <LW@...O-electronics.de>,
        Dong Aisheng <aisheng.dong@....com>,
        Bai Ping <ping.bai@....com>, Anson Huang <Anson.Huang@....com>,
        Octavian Purdila <octavian.purdila@....com>,
        Fabio Estevam <fabio.estevam@....com>,
        linux-pm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 4/5] ARM: dts: imx6sx: Use nvmem-cells for tempmon

On Fri, Jul 14, 2017 at 05:11:09PM +0300, Leonard Crestez wrote:
> On imx6sx accessing OCOTP directly is wrong because the ocotp clock
> needs to be enabled first. Use the nvmem-cells binding instead.
> 
> This requirement does not apply to older imx6qdl chips because there the
> ocotp access clock (clk_ipg_s) is always enabled.
> 
> This is visible by comparing the "System Clocks, Gating, and Override"
> tables (OCOTP rows) in the 6DQ and 6SX manuals:
> http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6SXRM.pdf
> http://www.nxp.com/assets/documents/data/en/reference-manuals/IMX6DQRM.pdf
> 
> This happens to work right now because the ocotp clock might be enabled
> for some other reason. In particular the it might be enabled from the
> bootloader and it only gets disabled late during boot in
> clk_disable_unused, after imx-thermal has completed probing.
> 
> If imx-thermal is compiled as a module then the system can hang on
> probe.
> 
> Reported-by: Lothar Waßmann <LW@...O-electronics.de>
> Signed-off-by: Leonard Crestez <leonard.crestez@....com>

I applied patch #4 and #5 to IMX tree for avoiding merge conflict.  Rui
will drop them from thermal tree.

Shawn