Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1391785

Re: [PATCH] PM / OPP: pass cpumask by reference

Show all headers | View raw

On Sat 2016-04-30 13:33:29, Arnd Bergmann wrote:
> The new use of dev_pm_opp_set_sharing_cpus resulted in a harmless compiler
> warning with CONFIG_CPUMASK_OFFSTACK=y:
> 
> drivers/cpufreq/mvebu-cpufreq.c: In function 'armada_xp_pmsu_cpufreq_init':
> include/linux/cpumask.h:550:25: error: passing argument 2 of 'dev_pm_opp_set_sharing_cpus' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
> 
> The problem here is that cpumask_var_t gets passed by reference, but
> by declaring a 'const cpumask_var_t' argument, only the pointer is
> constant, not the actual mask. This is harmless because the function
> does not actually modify the mask.
> 
> This patch changes the function prototypes for all of the related functions
> to pass a 'struct cpumask *' instead of 'cpumask_var_t', matching what
> most other such functions do in the kernel. This lets us mark all the
> other similar functions as taking a 'const' mask where possible,
> and it avoids the warning without any change in object code.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Fixes: 947bd567f7a5 ("mvebu: Use dev_pm_opp_set_sharing_cpus() to
mark OPP tables as shared")

Acked-by: Pavel Machek <pavel@ucw.cz>

(Hiding pointer into cpumask_var_t looks wrong to me, regardless of
const issues).


-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH] PM / OPP: pass cpumask by reference Arnd Bergmann <arnd@arndb.de> - 2016-04-30 13:40 +0200
  Re: [PATCH] PM / OPP: pass cpumask by reference Pavel Machek <pavel@ucw.cz> - 2016-05-01 12:10 +0200
  Re: [PATCH] PM / OPP: pass cpumask by reference Viresh Kumar <viresh.kumar@linaro.org> - 2016-05-02 10:20 +0200
  Re: [PATCH] PM / OPP: pass cpumask by reference Stephen Boyd <sboyd@codeaurora.org> - 2016-05-03 01:00 +0200
  Re: [PATCH] PM / OPP: pass cpumask by reference "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2016-05-06 01:40 +0200

csiph-web