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x86/olpc: fix 'logical not is only applied to the left hand side'
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The bitops compile-time optimization series revealed one more
problem in olpc-xo1-sci.c:send_ebook_state(), resulted in GCC
warnings:

arch/x86/platform/olpc/olpc-xo1-sci.c: In function 'send_ebook_state':
arch/x86/platform/olpc/olpc-xo1-sci.c:83:63: warning: logical not is only applied to the left hand side of comparison [-Wlogical-not-parentheses]
   83 |         if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
      |                                                               ^~
arch/x86/platform/olpc/olpc-xo1-sci.c:83:13: note: add parentheses around left hand side expression to silence this warning

Despite this code working as intended, this redundant double
negation of boolean value, together with comparing to `char`
with no explicit conversion to bool, makes compilers think
the author made some unintentional logical mistakes here.
Make it the other way around and negate the char instead
to silence the warnings.

Fixes: d2aa374 ("x86/olpc/xo1/sci: Produce wakeup events for buttons and switches")
Cc: stable@vger.kernel.org # 3.5+
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-and-tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
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Alexander Lobakin authored and Yury Norov committed Jul 15, 2022
1 parent f0dd891 commit 3a2ba42
Showing 1 changed file with 1 addition and 1 deletion.
2 changes: 1 addition & 1 deletion arch/x86/platform/olpc/olpc-xo1-sci.c
Original file line number Diff line number Diff line change
Expand Up @@ -80,7 +80,7 @@ static void send_ebook_state(void)
return;
}

if (!!test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == state)
if (test_bit(SW_TABLET_MODE, ebook_switch_idev->sw) == !!state)
return; /* Nothing new to report. */

input_report_switch(ebook_switch_idev, SW_TABLET_MODE, state);
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