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    SubjectRE: [PATCH 2/2] clk: imx: imx7d: remove clks_init_on array
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    Quoting Anson Huang (2018-10-08 01:34:59)
    > > Quoting Anson Huang (2018-09-03 00:20:53)
    > > > > > 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: shawnguo@kernel.org; s.hauer@pengutronix.de;
    > > > > > >>>>> kernel@pengutronix.de; Fabio Estevam
    > > > > > >>>>> <fabio.estevam@nxp.com>; mturquette@baylibre.com;
    > > > > > >>>>> sboyd@kernel.org; linux-arm-kernel@lists.infradead.org;
    > > > > > >>>>> linux-clk@vger.kernel.org; linux-kernel@vger.kernel.org
    > > > > > >>>>> Cc: dl-linux-imx <linux-imx@nxp.com>
    > > > > > >>>>> 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?
    > > > > >
    > > > >
    > > > > Why is that a goal?
    > > >
    > > > I do NOT think we should consider such case in this patch series,
    > > > whatever OP-TEE needs for its own feature, it should do necessary operations
    > > either in its driver or somewhere else by adding new patch.
    > > >
    > >
    > > Why can't we add clks to the op-tee node in DT's /firmware container?
    > > Then any clks in there can be turned on forever and left enabled by the linux
    > > driver?
    >
    > I did NOT run op-tee with Linux-next kernel before, can you advise more?

    Neither have I, so I can't advise more.

    > And I think if op-tee has such requirement,
    > can we have another patch to cover it?

    Yes.


    > I believe all other i.MX platforms also have same
    > requirements if considering op-tee support, so I think it should be another topic, what do you think?
    >

    I'm going to drop these patches from my review queue. Please resend them
    and please include the op-tee patches too.

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