On Thu, 2021-07-15 at 15:09 +0800, Tzung-Bi Shih wrote:

On Thu, Jul 15, 2021 at 10:32 AM Kewei Xu [off-list ref] wrote:

quoted

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.

quoted

        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.

Hi Tzung-Bi,

1. This Patch is not for fixing previous commit,it is just for the bad
speed formula.

2. I will fix this problem according to your suggestion in the next
patch.

Thanks
Kewei