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Re: [PATCH] powerpc: sysdev: cpm1: Optimise gpio bit calculation

From Segher Boessenkool <segher@kernel.crashing.org>
Newsgroups linux.kernel
Subject Re: [PATCH] powerpc: sysdev: cpm1: Optimise gpio bit calculation
Date 2017-03-10 14:20 +0100
Message-ID <tjsCC-4wB-25@gated-at.bofh.it> (permalink)
References <tj2RP-3lW-7@gated-at.bofh.it> <tjopj-1j2-1@gated-at.bofh.it> <tjqr9-2Qu-45@gated-at.bofh.it>
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On Fri, Mar 10, 2017 at 11:54:19AM +0100, Christophe LEROY wrote:
> gpio_get() and gpio_set() are used extensively by some GPIO based 
> drivers like SPI, NAND, so it may be worth it as it doesn't impair 
> readability (if anyone prefers, we could write  (1 << 31) >> i  instead 
> of  0x80000000 >> i )

1 << 31 is undefined behaviour, of course.


Segher

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[PATCH] powerpc: sysdev: cpm1: Optimise gpio bit calculation Christophe Leroy <christophe.leroy@c-s.fr> - 2017-03-09 10:50 +0100
  Re: [PATCH] powerpc: sysdev: cpm1: Optimise gpio bit calculation Michael Ellerman <mpe@ellerman.id.au> - 2017-03-10 09:50 +0100
    Re: [PATCH] powerpc: sysdev: cpm1: Optimise gpio bit calculation Christophe LEROY <christophe.leroy@c-s.fr> - 2017-03-10 12:00 +0100
      Re: [PATCH] powerpc: sysdev: cpm1: Optimise gpio bit calculation Segher Boessenkool <segher@kernel.crashing.org> - 2017-03-10 14:20 +0100
        Re: [PATCH] powerpc: sysdev: cpm1: Optimise gpio bit calculation Christophe LEROY <christophe.leroy@c-s.fr> - 2017-03-10 15:10 +0100
          Re: [PATCH] powerpc: sysdev: cpm1: Optimise gpio bit calculation Segher Boessenkool <segher@kernel.crashing.org> - 2017-03-10 15:40 +0100
            Re: [PATCH] powerpc: sysdev: cpm1: Optimise gpio bit calculation Christophe LEROY <christophe.leroy@c-s.fr> - 2017-03-10 15:50 +0100
              Re: [PATCH] powerpc: sysdev: cpm1: Optimise gpio bit calculation Segher Boessenkool <segher@kernel.crashing.org> - 2017-03-10 16:50 +0100
    Re: [PATCH] powerpc: sysdev: cpm1: Optimise gpio bit calculation Segher Boessenkool <segher@kernel.crashing.org> - 2017-03-10 14:10 +0100

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