[PATCH 8/8] i2c: mediatek: modify bus speed calculation formula

Tzung-Bi Shih tzungbi at google.com
Thu Jul 15 00:09:25 PDT 2021


On Thu, Jul 15, 2021 at 10:32 AM Kewei Xu <kewei.xu at mediatek.com> wrote:
> When clock-div is 0 or greater than 1, the bus speed
> calculated by the old speed calculation formula will be
> larger than the target speed. So we update the formula.
The patch sounds like a fix up.  Need a "Fixes" tag.

>         for (clk_div = 1; clk_div <= max_clk_div; clk_div++) {
>                 clk_src = parent_clk / clk_div;
> +               i2c->ac_timing.inter_clk_div = clk_div - 1;
Using the way to pass the parameter "inter_clk_div" to
mtk_i2c_calculate_speed() looks like a hack.  inter_clk_div is set
again[1] next to the for loop.

[1]: https://elixir.bootlin.com/linux/v5.14-rc1/source/drivers/i2c/busses/i2c-mt65xx.c#L831



I have no domain knowledge of what/how the patch fixes.  But if this
is a standalone fixup patch, suggest separating to an independent
patch.



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