Re: [PATCH v3 3/4] i2c: rk3x: new method to caculate i2c clocks
From: Julia Lawall
Date: Thu Jan 14 2016 - 09:51:31 EST
It looks like it would be an infinite loop?
julia
---------- Forwarded message ----------
Date: Thu, 14 Jan 2016 22:42:19 +0800
From: kbuild test robot <fengguang.wu@xxxxxxxxx>
To: kbuild@xxxxxx
Cc: Julia Lawall <julia.lawall@xxxxxxx>
Subject: Re: [PATCH v3 3/4] i2c: rk3x: new method to caculate i2c clocks
CC: kbuild-all@xxxxxx
In-Reply-To: <1452774699-57455-4-git-send-email-david.wu@xxxxxxxxxxxxxx>
TO: David Wu <david.wu@xxxxxxxxxxxxxx>
CC: heiko@xxxxxxxxx
CC: wsa@xxxxxxxxxxxxx, andy.shevchenko@xxxxxxxxx, dianders@xxxxxxxxxxxx, huangtao@xxxxxxxxxxxxxx, zyw@xxxxxxxxxxxxxx, cf@xxxxxxxxxxxxxx, xjq@xxxxxxxxxxxxxx, hl@xxxxxxxxxxxxxx, linux-arm-kernel@xxxxxxxxxxxxxxxxxxx, linux-rockchip@xxxxxxxxxxxxxxxxxxx, linux-gpio@xxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, David Wu <david.wu@xxxxxxxxxxxxxx>
Hi David,
[auto build test WARNING on wsa/i2c/for-next]
[also build test WARNING on v4.4 next-20160114]
[cannot apply to rockchip/for-next]
[if your patch is applied to the wrong git tree, please drop us a note to help improving the system]
url: https://github.com/0day-ci/linux/commits/David-Wu/i2c-rk3x-switch-to-i2c-generic-dt-parsing/20160114-203309
base: https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux i2c/for-next
:::::: branch date: 2 hours ago
:::::: commit date: 2 hours ago
>> drivers/i2c/busses/i2c-rk3x.c:793:23-34: WARNING: Unsigned expression compared with zero: data_hd_cnt >= 0
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 5fed4c320427dd34a909f9b408fadf297121924c
vim +793 drivers/i2c/busses/i2c-rk3x.c
5fed4c32 David Wu 2016-01-14 777 * for low (spend more time low).
5fed4c32 David Wu 2016-01-14 778 */
5fed4c32 David Wu 2016-01-14 779 extra_div = min_total_div - min_div_for_hold;
5fed4c32 David Wu 2016-01-14 780 extra_low_div = DIV_ROUND_UP(min_low_div * extra_div,
5fed4c32 David Wu 2016-01-14 781 min_div_for_hold);
5fed4c32 David Wu 2016-01-14 782
5fed4c32 David Wu 2016-01-14 783 t_output->div_low = min_low_div + extra_low_div;
5fed4c32 David Wu 2016-01-14 784 t_output->div_high = min_high_div + (extra_div - extra_low_div);
5fed4c32 David Wu 2016-01-14 785 }
5fed4c32 David Wu 2016-01-14 786
5fed4c32 David Wu 2016-01-14 787 /*
5fed4c32 David Wu 2016-01-14 788 * calculate sda data hold count by the rules, thd_sda_count:3
5fed4c32 David Wu 2016-01-14 789 * is a appropriate value to reduce calculated times.
5fed4c32 David Wu 2016-01-14 790 * tHD;sda = (l * s + 1) * T
5fed4c32 David Wu 2016-01-14 791 * tSU;sda = ((8 - s) * l + 1) * T
5fed4c32 David Wu 2016-01-14 792 */
5fed4c32 David Wu 2016-01-14 @793 for (data_hd_cnt = 3; data_hd_cnt >= 0; data_hd_cnt--) {
5fed4c32 David Wu 2016-01-14 794 max_hold_data_ns = DIV_ROUND_UP((data_hd_cnt
5fed4c32 David Wu 2016-01-14 795 * (t_output->div_low) + 1)
5fed4c32 David Wu 2016-01-14 796 * 1000000, clk_rate_khz);
5fed4c32 David Wu 2016-01-14 797 min_setup_data_ns = DIV_ROUND_UP(((8 - data_hd_cnt)
5fed4c32 David Wu 2016-01-14 798 * (t_output->div_low) + 1)
5fed4c32 David Wu 2016-01-14 799 * 1000000, clk_rate_khz);
5fed4c32 David Wu 2016-01-14 800 if ((max_hold_data_ns < spec_max_data_hold_ns) &&
5fed4c32 David Wu 2016-01-14 801 (min_setup_data_ns > spec_min_data_setup_ns)) {
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