Re: drivers/input/misc/iqs626a.c:1645:12: warning: stack frame size (2448) exceeds limit (2048) in 'iqs626_probe'

Jeff LaBundy
2021-11-29T01:01:57Z

Hi all,

On Fri, Nov 26, 2021 at 10:27:30PM +0800, kernel test robot wrote:
> Hi Jeff,
>
> FYI, the error/warning still remains.
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: a4849f6000e29235a2707f22e39da6b897bb9543
> commit: f1d2809de97adc422967b6de59f0f6199769eb93 Input: Add support for Azoteq IQS626A
> date: 8 months ago
> config: mips-randconfig-r013-20211124 (https://download.01.org/0day-ci/archive/20211126/202111262250.Y0l0olCY-lkp@intel.com/config)
> compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 67a1c45def8a75061203461ab0060c75c864df1c)
> reproduce (this is a W=1 build):
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # install mips cross compiling tool for clang build
> # apt-get install binutils-mips-linux-gnu
> # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f1d2809de97adc422967b6de59f0f6199769eb93
> git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> git fetch --no-tags linus master
> git checkout f1d2809de97adc422967b6de59f0f6199769eb93
> # save the config file to linux build tree
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=mips
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>

I was finally able to reproduce this report with the same steps; the
compiler appears to be inlining several functions called from inside
a for loop. I have posted a workaround in [1].

>
> All warnings (new ones prefixed by >>):
>
> >> drivers/input/misc/iqs626a.c:1645:12: warning: stack frame size (2448) exceeds limit (2048) in 'iqs626_probe' [-Wframe-larger-than]
> static int iqs626_probe(struct i2c_client *client)
> ^
> 1 warning generated.
> Assembler messages:
> Warning: a different -march was already specified, is now octeon
>
>
> vim +/iqs626_probe +1645 drivers/input/misc/iqs626a.c
>
> 1644
> > 1645 static int iqs626_probe(struct i2c_client *client)
> 1646 {
> 1647 struct iqs626_ver_info ver_info;
> 1648 struct iqs626_private *iqs626;
> 1649 int error;
> 1650
> 1651 iqs626 = devm_kzalloc(&client->dev, sizeof(*iqs626), GFP_KERNEL);
> 1652 if (!iqs626)
> 1653 return -ENOMEM;
> 1654
> 1655 i2c_set_clientdata(client, iqs626);
> 1656 iqs626->client = client;
> 1657
> 1658 iqs626->regmap = devm_regmap_init_i2c(client, &iqs626_regmap_config);
> 1659 if (IS_ERR(iqs626->regmap)) {
> 1660 error = PTR_ERR(iqs626->regmap);
> 1661 dev_err(&client->dev, "Failed to initialize register map: %d\n",
> 1662 error);
> 1663 return error;
> 1664 }
> 1665
> 1666 init_completion(&iqs626->ati_done);
> 1667
> 1668 error = regmap_raw_read(iqs626->regmap, IQS626_VER_INFO, &ver_info,
> 1669 sizeof(ver_info));
> 1670 if (error)
> 1671 return error;
> 1672
> 1673 if (ver_info.prod_num != IQS626_VER_INFO_PROD_NUM) {
> 1674 dev_err(&client->dev, "Unrecognized product number: 0x%02X\n",
> 1675 ver_info.prod_num);
> 1676 return -EINVAL;
> 1677 }
> 1678
> 1679 error = iqs626_parse_prop(iqs626);
> 1680 if (error)
> 1681 return error;
> 1682
> 1683 error = iqs626_input_init(iqs626);
> 1684 if (error)
> 1685 return error;
> 1686
> 1687 error = devm_request_threaded_irq(&client->dev, client->irq,
> 1688 NULL, iqs626_irq, IRQF_ONESHOT,
> 1689 client->name, iqs626);
> 1690 if (error) {
> 1691 dev_err(&client->dev, "Failed to request IRQ: %d\n", error);
> 1692 return error;
> 1693 }
> 1694
> 1695 if (!wait_for_completion_timeout(&iqs626->ati_done,
> 1696 msecs_to_jiffies(2000))) {
> 1697 dev_err(&client->dev, "Failed to complete ATI\n");
> 1698 return -ETIMEDOUT;
> 1699 }
> 1700
> 1701 /*
> 1702 * The keypad may include one or more switches and is not registered
> 1703 * until ATI is complete and the initial switch states are read.
> 1704 */
> 1705 error = input_register_device(iqs626->keypad);
> 1706 if (error)
> 1707 dev_err(&client->dev, "Failed to register keypad: %d\n", error);
> 1708
> 1709 return error;
> 1710 }
> 1711
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[1] https://patchwork.kernel.org/patch/12643273

Kind regards,
Jeff LaBundy