Re: [PATCH v2 2/2] i2c: mediatek: Add i2c ac-timing adjust support

[Valdis KlÄtnieks]

On Tue, 19 May 2020 10:57:53 +0800, Qii Wang said:

> (1000000000 * (sample_cnt + 1)) / clk_src value is a 32-bit, (1000000000
> * (sample_cnt + 1)) will over 32-bit if sample_cnt is 7.
>
> I think 1000000000 and clk_src is too big, maybe I can reduce then with
> be divided all by 1000.

Yes, it's definitely too big, the 3 DIV_ROUND_UP calls in  mtk_i2c_check_ac_timing()
end up causing a build issue during modpost on a 32-bit RPi4:

ERROR: modpost: "__aeabi_uldivmod" [drivers/i2c/busses/i2c-mt65xx.ko] undefined!
ERROR: modpost: "__aeabi_ldivmod" [drivers/i2c/busses/i2c-mt65xx.ko] undefined!

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