linux-kernel - Re: [PATCH v2] HID: pidff: Fix condition effect bit clearing

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Message-ID: <20260205004106.GA2386589@ax162>
Date: Wed, 4 Feb 2026 17:41:06 -0700
From: Nathan Chancellor <nathan@...nel.org>
To: kernel test robot <lkp@...el.com>
Cc: Tomasz Pakuła <tomasz.pakula.oficjalny@...il.com>,
	jikos@...nel.org, bentiss@...nel.org, llvm@...ts.linux.dev,
	oe-kbuild-all@...ts.linux.dev, oleg@...arenk.ooo,
	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] HID: pidff: Fix condition effect bit clearing

On Thu, Feb 05, 2026 at 05:07:56AM +0800, kernel test robot wrote:
> Hi Tomasz,
> 
> kernel test robot noticed the following build warnings:
> 
> [auto build test WARNING on hid/for-next]
> [also build test WARNING on linus/master v6.19-rc8 next-20260204]
> [If your patch is applied to the wrong git tree, kindly drop us a note.
> And when submitting patch, we suggest to use '--base' as documented in
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
> 
> url:    https://github.com/intel-lab-lkp/linux/commits/Tomasz-Paku-a/HID-pidff-Fix-condition-effect-bit-clearing/20260204-213418
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git for-next
> patch link:    https://lore.kernel.org/r/20260204133138.475880-1-tomasz.pakula.oficjalny%40gmail.com
> patch subject: [PATCH v2] HID: pidff: Fix condition effect bit clearing
> config: x86_64-rhel-9.4-rust (https://download.01.org/0day-ci/archive/20260205/202602050440.e5LEMod6-lkp@intel.com/config)
> compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
> rustc: rustc 1.88.0 (6b00bc388 2025-06-23)
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260205/202602050440.e5LEMod6-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@...el.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202602050440.e5LEMod6-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>):
> 
> >> drivers/hid/usbhid/hid-pidff.c:1456:7: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical]
>     1456 |                 if (test_and_clear_bit(FF_SPRING, dev->ffbit)   |
>          |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     1457 |                     test_and_clear_bit(FF_DAMPER, dev->ffbit)   |
>          |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     1458 |                     test_and_clear_bit(FF_FRICTION, dev->ffbit) |
>          |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>          |                                                                 ||
>     1459 |                     test_and_clear_bit(FF_INERTIA, dev->ffbit))
>          |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>    drivers/hid/usbhid/hid-pidff.c:1456:7: note: cast one or both operands to int to silence this warning
> >> drivers/hid/usbhid/hid-pidff.c:1456:7: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical]
>     1456 |                 if (test_and_clear_bit(FF_SPRING, dev->ffbit)   |
>          |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     1457 |                     test_and_clear_bit(FF_DAMPER, dev->ffbit)   |
>          |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>          |                                                                 ||
>     1458 |                     test_and_clear_bit(FF_FRICTION, dev->ffbit) |
>          |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>    drivers/hid/usbhid/hid-pidff.c:1456:7: note: cast one or both operands to int to silence this warning
> >> drivers/hid/usbhid/hid-pidff.c:1456:7: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical]
>     1456 |                 if (test_and_clear_bit(FF_SPRING, dev->ffbit)   |
>          |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>          |                                                                 ||
>     1457 |                     test_and_clear_bit(FF_DAMPER, dev->ffbit)   |
>          |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>    drivers/hid/usbhid/hid-pidff.c:1456:7: note: cast one or both operands to int to silence this warning
>    3 warnings generated.

As the use of the bitwise operation is intentional here per the comment,
I think going back to v1 to avoid introducing this warning would be
better than casting one of these operands to int to silence it with the
v2 structuring of the code. v1 matches what I have done elsewhere in the
kernel to make it obvious that each function should be called (without a
comment):

  2e70570656ad ("drm/i915: Avoid bitwise vs logical OR warning in snb_wm_latency_quirk()")
  a02dcde595f7 ("Input: touchscreen - avoid bitwise vs logical OR warning")

Cheers,
Nathan