Re: [PATCH] clk: divider: fix incorrect usage of container_of

From: Stephen Boyd
Date: Thu Dec 21 2017 - 13:38:43 EST

On 12/21, Jerome Brunet wrote:
> divider_recalc_rate() is an helper function used by clock divider of
> different types, so the structure containing the 'hw' pointer is not
> always a 'struct clk_divider'
> At the following line:
> > div = _get_div(table, val, flags, divider->width);
> in several cases, the value of 'divider->width' is garbage as the actual
> structure behind this memory is not a 'struct clk_divider'
> Fortunately, this width value is used by _get_val() only when
> CLK_DIVIDER_MAX_AT_ZERO flag is set. This has never been the case so
> far when the structure is not a 'struct clk_divider'. This is probably
> why we did not notice this bug before
> Fixes: afe76c8fd030 ("clk: allow a clk divider with max divisor when zero")
> Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> ---
> Hi Stephen, Mike,
> In addition to clock, this patch also touch the rtc and drm directories.
> As it is changing the API of the helper function, I have this fix in a
> single commit to avoid breaking bisect.
> Please let me know if you prefer to do differently.

Looks good. Thanks for catching this before it became a real
problem. It would be good to get acks from DRM and RTC

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