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  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]
Date:   Fri, 31 Aug 2018 10:01:44 +0200
From:   Jerome Forissier <>
To:     Stephen Boyd <>,
        "" <>,
        "" <>,
        "" <>,
        "" <>,
        "" <>,
        "" <>,
        Anson Huang <>,
        Fabio Estevam <>,
        Peng Fan <>, Rob Herring <>
Cc:     dl-linux-imx <>
Subject: Re: [PATCH 2/2] clk: imx: imx7d: remove clks_init_on array

On 08/31/2018 03:29 AM, Stephen Boyd wrote:
> Quoting Peng Fan (2018-08-12 18:15:41)
>> Hi Anson,
>>>>> -----Original Message-----
>>>>> From: Anson Huang
>>>>> Sent: 2018年8月8日 12:39
>>>>> To:;;
>>>>>; Fabio Estevam <>;
>>>>> Cc: dl-linux-imx <>
>>>>> Subject: [PATCH 2/2] clk: imx: imx7d: remove clks_init_on array
>>>>> Clock framework will enable those clocks registered with
>>>>> CLK_IS_CRITICAL flag, so no need to have clks_init_on array during
>>>>> clock
>>>> initialization now.
>>>> Will it be more flexible to parse dts saying "critical-clocks = <xxx>"
>>>> or "init-on-arrary=<xxx>"
>>>> and enable those clocks?
>>> Parsing the clocks arrays from dtb is another way of enabling critical clocks, but
>>> for current i.MX6/7 platforms, we implement it in same way as most of other
>>> SoCs, currently I did NOT see any necessity of putting them in dtb, just adding
>>> flag during clock registering is more simple, if there is any special requirement
>>> for different clocks set to be enabled, then we can add support to enable the
>>> method of parsing critical-clocks from dtb. Just my two cents.
>> Thinking about OP-TEE want to use one device, but it's clocks are registered
>> by Linux, because there is no module in Linux side use it, it will shutdown the clock,
>> which cause OP-TEE could not access the device.
>> Then people have to modify clk code to add CLK_IS_CRITICAL flag to make sure
>> the clocks are not shutdown by Linux.
>> However adding a new property in clk node and let driver code parse the dts,
>> there is no need to modify clk driver code when OP-TEE needs another device clock.
> If OP-TEE needs linux to keep things on then why can't the OP-TEE driver
> in Linux probe, acquire clocks, and keep the clks enabled forever?

Sounds reasonable, but how could this be done without introducing
platform-specific stuff in the OP-TEE driver?

> _______________________________________________
> linux-arm-kernel mailing list

Powered by blists - more mailing lists