public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation•org>
To: Geert Uytterhoeven <geert@linux-m68k•org>
Cc: linux-fbdev@vger•kernel.org, "Greg KH" <gregkh@suse•de>,
	"Lars-Peter Clausen" <lars@metafoo•de>,
	"James Hogan" <james@albanarts•com>,
	"David Airlie" <airlied@linux•ie>,
	"Daniel Vetter" <daniel.vetter@ffwll•ch>,
	linux-omap@vger•kernel.org,
	"Jesse Barnes" <jbarnes@virtuousgeek•org>,
	"James E.J. Bottomley" <jejb@parisc-linux•org>,
	"David S. Miller" <davem@davemloft•net>,
	"Paul Mackerras" <paulus@samba•org>,
	"Liam Girdwood" <lrg@slimlogic•co.uk>,
	"Kyle McMartin" <kyle@mcmartin•ca>, "Jiri Slaby" <jslaby@suse•cz>,
	"Thomas Gleixner" <tglx@linutronix•de>,
	"Caglar Akyuz" <caglar@bilkon-kontrol•com.tr>,
	devel@driverdev•osuosl.org,
	"Alberto Panizzo" <maramaopercheseimorto@gmail•com>,
	"Phil Edworthy" <phil.edworthy@renesas•com>,
	xen-devel@lists•xensource.com,
	"Russell King" <linux@arm•linux.org.uk>,
	"Kuninori Morimoto" <kuninori.morimoto.gx@renesas•com>,
	"Wu Zhangjin" <wuzhangjin@gmail•com>,
	"Florian Tobias Schandinat" <FlorianSchandinat@gmx•de>,
	"Lionel Debroux" <lionel_debroux@yahoo•fr>,
	"Helge Deller" <deller@gmx•de>,
	"Kay Sievers" <kay.sievers@vrfy•org>,
	"James Morris" <jmorris@namei•org>,
	"Kevin Hilman" <khilman@deeprootsystems•com>,
	"Tony Lindgren" <tony@atomide•com>,
	"Ben Skeggs" <bskeggs@redhat•com>,
	"Andres Salomon" <dilinger@queued•net>,
	"Julia Lawall" <julia@diku•dk>,
	"Dave Airlie" <airlied@redhat•com>,
	"Kees Cook" <kees.cook@canonical•com>,
	"Francisco Jerez" <currojerez@riseup•net>,
	"Abhijeet Dharmapurikar" <adharmap@codeaurora•org>,
	"Marcin Slusarz" <marcin.slusarz@gmail•com>,
	cbe-oss-dev@lists•ozlabs.org, linuxppc-dev@lists•ozlabs.org,
	"Ondrej Zary" <linux@rainbow-software•org>,
	"Denys Vlasenko" <vda.linux@googlemail•com>,
	"Konrad Rzeszutek Wilk" <konrad.wilk@oracle•com>,
	linux-kernel@vger•kernel.org, "Namhyung Kim" <namhyung@gmail•com>,
	"Rusty Russell" <rusty@rustcorp•com.au>,
	"Werner Fink" <werner@suse•de>,
	linux-geode@lists•infradead.org, torbenh <torbenh@gmx•de>,
	"Jean Delvare" <khali@linux-fr•org>,
	"Magnus Damm" <damm@opensource•se>,
	"Jeremy Fitzhardinge" <jeremy.fitzhardinge@citrix•com>,
	dri-devel@lists•freedesktop.org, "Daniel Mack" <daniel@caiaq•de>,
	"Nicolas Pitre" <nicolas.pitre@canonical•com>,
	"Dan Williams" <dan.j.williams@intel•com>,
	virtualization@lists•linux-foundation.org,
	"Ingo Molnar" <mingo@elte•hu>,
	linux-arm-kernel@lists•infradead.org,
	"Thomas Gleixner" <tglx@tglx•de>,
	"Daniel Walker" <dwalker@codeaurora•org>,
	"Linus Walleij" <linus.walleij@stericsson•com>,
	linux-parisc@vger•kernel.org,
	"Geoff Levand" <geoff@infradead•org>,
	"Jiri Kosina" <jkosina@suse•cz>,
	"Mark Brown" <broonie@opensource•wolfsonmicro.com>,
	"Jerome Glisse" <jglisse@redhat•com>,
	"Ralf Baechle" <ralf@linux-mips•org>,
	"Alexey Dobriyan" <adobriyan@gmail•com>,
	"Guy Martin" <gmsoft@tuxicoman•be>,
	"Ondrej Zajicek" <santiago@crfreenet•org>,
	"Paul Mundt" <lethal@linux-sh•org>,
	"Arnd Bergmann" <arnd@arndb•de>, "Takashi Iwai" <tiwai@suse•de>,
	"Jason Wessel" <jason.wessel@windriver•com>,
	"Alex Deucher" <alexdeucher@gmail•com>,
	"Tejun Heo" <tj@kernel•org>,
	"Antonino Daplas" <adaplas@gmail•com>,
	"Guennadi Liakhovetski" <g.liakhovetski@gmx•de>,
	"Marcin Kościelnicki" <koriakin@0x04•net>,
	"David Brown" <davidb@codeaurora•org>
Subject: Re: [PATCH] change acquire/release_console_sem() to console_lock/unlock()
Date: Fri, 21 Jan 2011 00:23:23 -0800	[thread overview]
Message-ID: <20110121002323.e9cbf9ae.akpm@linux-foundation.org> (raw)
In-Reply-To: <AANLkTinN2+pNGk1hwrcMhH5qDNZK=Egrw7P6c-cdJTmH@mail.gmail.com>

On Fri, 21 Jan 2011 09:10:06 +0100 Geert Uytterhoeven <geert@linux-m68k•org> wrote:

> include/linux/mutex.h:
> 
> /*
>  * NOTE: mutex_trylock() follows the spin_trylock() convention,
>  *       not the down_trylock() convention!
>  *
>  * Returns 1 if the mutex has been acquired successfully, and 0 on contention.
>  */
> extern int mutex_trylock(struct mutex *lock);
> 
> So that's why the return value was inverted (when treating it as a boolean).
> I can understand that.
> 
> However:
> 
> +/**
> + * console_trylock - try to lock the console system for exclusive use.
> + *
> + * Tried to acquire a lock which guarantees that the caller has
> + * exclusive access to the console system and the console_drivers list.
> + *
> + * returns -1 on success, and 0 on failure to acquire the lock.
> + */
> +int console_trylock(void)
> 
> So this one returns -1 on success, not 1? Why?

Yup.  All callers just test for non-zero, so...

--- a/kernel/printk.c~change-acquire-release_console_sem-to-console_lock-unlock-fix-2
+++ a/kernel/printk.c
@@ -1058,7 +1058,7 @@ EXPORT_SYMBOL(console_lock);
  * Tried to acquire a lock which guarantees that the caller has
  * exclusive access to the console system and the console_drivers list.
  *
- * returns -1 on success, and 0 on failure to acquire the lock.
+ * returns 1 on success, and 0 on failure to acquire the lock.
  */
 int console_trylock(void)
 {
@@ -1070,7 +1070,7 @@ int console_trylock(void)
 	}
 	console_locked = 1;
 	console_may_schedule = 0;
-	return -1;
+	return 1;
 }
 EXPORT_SYMBOL(console_trylock);
 
_

      reply	other threads:[~2011-01-21  8:23 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-01-20 15:58 [PATCH] change acquire/release_console_sem() to console_lock/unlock() Torben Hohn
2011-01-20 16:34 ` Greg KH
2011-01-20 16:55   ` torbenh
2011-01-20 20:35     ` Andrew Morton
2011-01-21  8:10       ` Geert Uytterhoeven
2011-01-21  8:23         ` Andrew Morton [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20110121002323.e9cbf9ae.akpm@linux-foundation.org \
    --to=akpm@linux-foundation$(echo .)org \
    --cc=FlorianSchandinat@gmx$(echo .)de \
    --cc=adaplas@gmail$(echo .)com \
    --cc=adharmap@codeaurora$(echo .)org \
    --cc=adobriyan@gmail$(echo .)com \
    --cc=airlied@linux$(echo .)ie \
    --cc=airlied@redhat$(echo .)com \
    --cc=alexdeucher@gmail$(echo .)com \
    --cc=arnd@arndb$(echo .)de \
    --cc=broonie@opensource$(echo .)wolfsonmicro.com \
    --cc=bskeggs@redhat$(echo .)com \
    --cc=caglar@bilkon-kontrol$(echo .)com.tr \
    --cc=cbe-oss-dev@lists$(echo .)ozlabs.org \
    --cc=currojerez@riseup$(echo .)net \
    --cc=damm@opensource$(echo .)se \
    --cc=dan.j.williams@intel$(echo .)com \
    --cc=daniel.vetter@ffwll$(echo .)ch \
    --cc=daniel@caiaq$(echo .)de \
    --cc=davem@davemloft$(echo .)net \
    --cc=davidb@codeaurora$(echo .)org \
    --cc=deller@gmx$(echo .)de \
    --cc=devel@driverdev$(echo .)osuosl.org \
    --cc=dilinger@queued$(echo .)net \
    --cc=dri-devel@lists$(echo .)freedesktop.org \
    --cc=dwalker@codeaurora$(echo .)org \
    --cc=g.liakhovetski@gmx$(echo .)de \
    --cc=geert@linux-m68k$(echo .)org \
    --cc=geoff@infradead$(echo .)org \
    --cc=gmsoft@tuxicoman$(echo .)be \
    --cc=gregkh@suse$(echo .)de \
    --cc=james@albanarts$(echo .)com \
    --cc=jason.wessel@windriver$(echo .)com \
    --cc=jbarnes@virtuousgeek$(echo .)org \
    --cc=jejb@parisc-linux$(echo .)org \
    --cc=jeremy.fitzhardinge@citrix$(echo .)com \
    --cc=jglisse@redhat$(echo .)com \
    --cc=jkosina@suse$(echo .)cz \
    --cc=jmorris@namei$(echo .)org \
    --cc=jslaby@suse$(echo .)cz \
    --cc=julia@diku$(echo .)dk \
    --cc=kay.sievers@vrfy$(echo .)org \
    --cc=kees.cook@canonical$(echo .)com \
    --cc=khali@linux-fr$(echo .)org \
    --cc=khilman@deeprootsystems$(echo .)com \
    --cc=konrad.wilk@oracle$(echo .)com \
    --cc=koriakin@0x04$(echo .)net \
    --cc=kuninori.morimoto.gx@renesas$(echo .)com \
    --cc=kyle@mcmartin$(echo .)ca \
    --cc=lars@metafoo$(echo .)de \
    --cc=lethal@linux-sh$(echo .)org \
    --cc=linus.walleij@stericsson$(echo .)com \
    --cc=linux-arm-kernel@lists$(echo .)infradead.org \
    --cc=linux-fbdev@vger$(echo .)kernel.org \
    --cc=linux-geode@lists$(echo .)infradead.org \
    --cc=linux-kernel@vger$(echo .)kernel.org \
    --cc=linux-omap@vger$(echo .)kernel.org \
    --cc=linux-parisc@vger$(echo .)kernel.org \
    --cc=linux@arm$(echo .)linux.org.uk \
    --cc=linux@rainbow-software$(echo .)org \
    --cc=linuxppc-dev@lists$(echo .)ozlabs.org \
    --cc=lionel_debroux@yahoo$(echo .)fr \
    --cc=lrg@slimlogic$(echo .)co.uk \
    --cc=maramaopercheseimorto@gmail$(echo .)com \
    --cc=marcin.slusarz@gmail$(echo .)com \
    --cc=mingo@elte$(echo .)hu \
    --cc=namhyung@gmail$(echo .)com \
    --cc=nicolas.pitre@canonical$(echo .)com \
    --cc=paulus@samba$(echo .)org \
    --cc=phil.edworthy@renesas$(echo .)com \
    --cc=ralf@linux-mips$(echo .)org \
    --cc=rusty@rustcorp$(echo .)com.au \
    --cc=santiago@crfreenet$(echo .)org \
    --cc=tglx@linutronix$(echo .)de \
    --cc=tglx@tglx$(echo .)de \
    --cc=tiwai@suse$(echo .)de \
    --cc=tj@kernel$(echo .)org \
    --cc=tony@atomide$(echo .)com \
    --cc=torbenh@gmx$(echo .)de \
    --cc=vda.linux@googlemail$(echo .)com \
    --cc=virtualization@lists$(echo .)linux-foundation.org \
    --cc=werner@suse$(echo .)de \
    --cc=wuzhangjin@gmail$(echo .)com \
    --cc=xen-devel@lists$(echo .)xensource.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox