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    SubjectRe: [PATCH v7 12/34] i2c: tegra: Use clk-bulk helpers
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    17.09.2020 14:38, Thierry Reding пишет:
    > On Wed, Sep 09, 2020 at 01:39:44AM +0300, Dmitry Osipenko wrote:
    >> Use clk-bulk helpers and factor out clocks initialization into separate
    >> function in order to make code cleaner.
    >>
    >> The clocks initialization now performed after reset-control initialization
    >> in order to avoid a noisy -PROBE_DEFER errors on T186+ from the clk-bulk
    >> helper which doesn't silence this error code. Hence reset_control_get()
    >> now may return -EPROBE_DEFER on newer Tegra SoCs because they use BPMP
    >> driver that provides reset controls and BPMP doesn't come up early during
    >> boot. Previously rst was protected by the clocks retrieval and now this
    >> patch makes dev_err_probe() to be used for the rst error handling.
    >>
    >> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
    >> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
    >> ---
    >> drivers/i2c/busses/i2c-tegra.c | 187 ++++++++++++---------------------
    >> 1 file changed, 67 insertions(+), 120 deletions(-)
    >
    > This is tempting from a diffstat point of view, but the downside is that
    > we can now no longer validate that all of the necessary clocks are given
    > in device tree.
    >
    > Previously the driver would fail to probe the I2C controller if any of
    > the expected clocks were not defined in device tree, but now it's just
    > going to continue without it and not give any indication as to what's
    > wrong.

    The clocks can't be missed randomly in a device-tree because they are a
    part of the core tegra.dtsi

    The tegra-i2c DT binding isn't converted to YAML, but once it will be,
    then the dtbs_check will tell you about such obvious problems like a
    missing mandatory property.

    Even if clock is missing, then you won't miss this problem since I2C
    shouldn't work in that case.

    There is a Qualcomm I2C driver that already uses clk_bulk_get_all() and
    doesn't worry about "accidentally" missing clocks.

    It's still possible to add the clk-num checking, but it should be
    unpractical. We could always add it later on if there will be a real
    incident. Do you agree?

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