linaro-dev March 2013

linaro-dev@lists.linaro.org

51 participants
53 discussions

[PATCH V2 Resend 0/4] Create sched_select_cpu() and use it for workqueues and timers

by Viresh Kumar

Hi All, This is V2 Resend of my sched_select_cpu() work. Resend because didn't got much attention on V2. Including more guys now in cc :) In order to save power, it would be useful to schedule work onto non-IDLE cpus instead of waking up an IDLE one. To achieve this, we need scheduler to guide kernel frameworks (like: timers & workqueues) on which is the most preferred CPU that must be used for these tasks. This patchset is about implementing this concept. - The first patch adds sched_select_cpu() routine which returns the preferred cpu which is non-idle. - Second patch removes idle_cpu() calls from timer & hrtimer. - Third patch is about adapting this change in workqueue framework. - Fourth patch add migration capability in running timer Earlier discussions over v1 can be found here: http://www.mail-archive.com/linaro-dev@lists.linaro.org/msg13342.html Earlier discussions over this concept were done at last LPC: http://summit.linuxplumbersconf.org/lpc-2012/meeting/90/lpc2012-sched-timer… Module created for testing this behavior is present here: http://git.linaro.org/gitweb?p=people/vireshk/module.git;a=summary Following are the steps followed in test module: 1. Run single work on each cpu 2. This work will start a timer after x (tested with 10) jiffies of delay 3. Timer routine queues a work... (This may be called from idle or non-idle cpu) and starts the same timer again STEP 3 is done for n number of times (i.e. queuing n works, one after other) 4. All works will call a single routine, which will count following per cpu: - Total works processed by a CPU - Total works processed by a CPU, which are queued from it - Total works processed by a CPU, which aren't queued from it Setup: ----- - ARM Vexpress TC2 - big.LITTLE CPU - Core 0-1: A15, 2-4: A7 - rootfs: linaro-ubuntu-nano Results: ------- Without Workqueue Modification, i.e. PATCH 3/3: [ 2493.022335] Workqueue Analyser: works processsed by CPU0, Total: 1000, Own: 0, migrated: 0 [ 2493.047789] Workqueue Analyser: works processsed by CPU1, Total: 1000, Own: 0, migrated: 0 [ 2493.072918] Workqueue Analyser: works processsed by CPU2, Total: 1000, Own: 0, migrated: 0 [ 2493.098576] Workqueue Analyser: works processsed by CPU3, Total: 1000, Own: 0, migrated: 0 [ 2493.123702] Workqueue Analyser: works processsed by CPU4, Total: 1000, Own: 0, migrated: 0 With Workqueue Modification, i.e. PATCH 3/3: [ 2493.022335] Workqueue Analyser: works processsed by CPU0, Total: 1002, Own: 999, migrated: 3 [ 2493.047789] Workqueue Analyser: works processsed by CPU1, Total: 998, Own: 997, migrated: 1 [ 2493.072918] Workqueue Analyser: works processsed by CPU2, Total: 1013, Own: 996, migrated: 17 [ 2493.098576] Workqueue Analyser: works processsed by CPU3, Total: 998, Own: 993, migrated: 5 [ 2493.123702] Workqueue Analyser: works processsed by CPU4, Total: 989, Own: 987, migrated: 2 V2->V2-Resend ------------- - Included timer migration patch in the same thread. V1->V2 ----- - New SD_* macros removed now and earlier ones used - sched_select_cpu() rewritten and it includes the check on current cpu's idleness. - cpu_idle() calls from timer and hrtimer removed now. - Patch 2/3 from V1, removed as it doesn't apply to latest workqueue branch from tejun. - CONFIG_MIGRATE_WQ removed and so is wq_select_cpu() - sched_select_cpu() called only from __queue_work() - got tejun/for-3.7 branch in my tree, before making workqueue changes. Viresh Kumar (4): sched: Create sched_select_cpu() to give preferred CPU for power saving timer: hrtimer: Don't check idle_cpu() before calling get_nohz_timer_target() workqueue: Schedule work on non-idle cpu instead of current one timer: Migrate running timer include/linux/sched.h | 16 ++++++++++-- include/linux/timer.h | 2 ++ kernel/hrtimer.c | 2 +- kernel/sched/core.c | 69 +++++++++++++++++++++++++++++++-------------------- kernel/timer.c | 50 ++++++++++++++++++++++--------------- kernel/workqueue.c | 4 +-- 6 files changed, 91 insertions(+), 52 deletions(-) -- 1.7.12.rc2.18.g61b472e

10 years, 5 months

[Query]: Can people post to this mailing list without subscription?

by Viresh Kumar

Hi Guys, I really don't know whom to direct this mail to and hence the wide spread. Problem: When we send a mail to kernel mailing lists with linaro-dev or linaro-kernel in cc, and we get replies to those mails, sometimes the mails from outside people doesn't reach us back on linaro mailing lists. And i hope the reason behind that is those people aren't subscribed to these lists. For me it makes some sense to allow anyone to send mails to this list. Can that request be considered? I believe the idea behind blocking such use is for protecting against spam mails, but these mails/replies are really important and we certainly need them delivered to us. One solution (don't know if its possible) would be to monitor mails from non-subscribers and few people from Linaro can permit them on daily/hourly basis, so that we don't get any spam mails, but that would be a burden. -- viresh

10 years, 7 months

[PATCH] genirq: Add default affinity mask command line option

by Punit Agrawal

I am attaching a patch by Thomas Gleixner which adds a kernel command line parameter to set the defauilt IRQ affinity mask. Could you please integrate this in your tree for the next Linaro release? I've been using this patch for sometime now and it doesn't introduce any regressions. There is a possibility that this patch will make it upstream via the RT patches in the near future but in the meanwhile, we'd like to carry this patch as well. Cheers, Punit >From 52a7d44f58a262e166575abc57aa0bd3bfc8cfbb Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx(a)linutronix.de> Date: Fri, 25 May 2012 16:59:47 +0200 Subject: [PATCH] genirq: Add default affinity mask command line option If we isolate CPUs, then we don't want random device interrupts on them. Even w/o the user space irq balancer enabled we can end up with irqs on non boot cpus. Allow to restrict the default irq affinity mask. Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de> --- Documentation/kernel-parameters.txt | 9 +++++++++ kernel/irq/irqdesc.c | 21 +++++++++++++++++++-- 2 files changed, 28 insertions(+), 2 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 7d82468..00fedab 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1164,6 +1164,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted. See comment before ip2_setup() in drivers/char/ip2/ip2base.c. + irqaffinity= [SMP] Set the default irq affinity mask + Format: + <cpu number>,...,<cpu number> + or + <cpu number>-<cpu number> + (must be a positive range in ascending order) + or a mixture + <cpu number>,...,<cpu number>-<cpu number> + irqfixup [HW] When an interrupt is not handled search all handlers for it. Intended to get systems with badly broken diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 192a302..473b2b6 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -23,10 +23,27 @@ static struct lock_class_key irq_desc_lock_class; #if defined(CONFIG_SMP) +static int __init irq_affinity_setup(char *str) +{ + zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT); + cpulist_parse(str, irq_default_affinity); + /* + * Set at least the boot cpu. We don't want to end up with + * bugreports caused by random comandline masks + */ + cpumask_set_cpu(smp_processor_id(), irq_default_affinity); + return 1; +} +__setup("irqaffinity=", irq_affinity_setup); + static void __init init_irq_default_affinity(void) { - alloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT); - cpumask_setall(irq_default_affinity); +#ifdef CONFIG_CPUMASK_OFFSTACK + if (!irq_default_affinity) + zalloc_cpumask_var(&irq_default_affinity, GFP_NOWAIT); +#endif + if (cpumask_empty(irq_default_affinity)) + cpumask_setall(irq_default_affinity); } #else static void __init init_irq_default_affinity(void) -- 1.7.9.5

10 years, 11 months

Google Summer of Code - interested?

by Steve McIntyre

Hi folks, As a follow-up to my work in LEG on assembly scanning and optimisation for AArch64, we're considering applying as a mentoring organisation for the Google Summer of Code [1] this year. There's quite a lot of code out there that may benefit from porting (whether for support of AArch64 or for better performance) and I think we could usefully get some students involved to help with this. I'm planning on doing the bureacracy for the SoC application in the next few days. So, the reason why I'm posting about that here: is anybody else interested in joining in? Are there any other projects in/around Linaro where: a) a student could do some useful work; b) we have somebody prepared to act as a mentor ? If so, please let me know. The more ideas we can suggest for summer projects like this, the more likely we are to be accepted as a mentoring organisation by Google. [1] http://www.google-melange.com/gsoc/homepage/google/gsoc2013 Cheers, -- Steve McIntyre steve.mcintyre(a)linaro.org <http://www.linaro.org/> Linaro.org | Open source software for ARM SoCs

11 years

cross build packages for quantal

by Pascal PAILLET-LME

Hi, I'm trying to cross build some packages for ubuntu quantal following this wiki: https://wiki.linaro.org/Platform/DevPlatform/CrossCompile/UsingXdeb we would like to be able to build packages like gstreamer. today, I'm able to compile busybox and grep but no gstreamer or gstreamer plugins Here is my HowTo: sudo su debootstrap quantal m-xdeb chmod 777 m-xdeb/etc/apt/sources.list vi m-xdeb/etc/apt/sources.list deb [arch=armhf] http://ports.ubuntu.com/ quantal main universe deb-src http://ports.ubuntu.com/ quantal main universe deb http://archive.ubuntu.com/ubuntu quantal main universe sudo chroot m-xdeb mount -t proc proc /proc mount -t devpts none /dev/pts export LC_ALL=C adduser build adduser build sudo apt-get update apt-get install -y xdeb gcc-arm-linux-gnueabihf g++-arm-linux-gnueabihf dpkg --add-architecture armhf exit sudo chroot m-xdeb su - build export LC_ALL=C here are the results: xdeb -a armhf --only-explicit --no-lintian --apt-source grep OK xdeb -a armhf --no-lintian --apt-source gstreamer1.0 Fails: Dependency cycle: [u'cairo', u'libxt', u'glib2.0', u'dbus-python', u'dbus-glib'] xdeb -a armhf --only-explicit --no-lintian --apt-source gstreamer1.0 Fails: /home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/Gst-1.0.c:580:3: warning: implicit declaration of function 'gst_init' [-Wimplicit-function-declaration] g-ir-scanner: link: ../libtool --mode=link --tag=CC arm-linux-gnueabihf-gcc -std=gnu99 -o /home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/Gst-1.0 -export-dynamic /home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/Gst-1.0.o -L. libgstreamer-1.0.la -Wl,--export-dynamic -pthread -L/usr/arm-linux-gnueabihf/lib -lgio-2.0 -lgobject-2.0 -lgmodule-2.0 -lgthread-2.0 -lrt -lglib-2.0 libtool: link: arm-linux-gnueabihf-gcc -std=gnu99 -o /home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/.libs/Gst-1.0 /home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/Gst-1.0.o -Wl,--export-dynamic -pthread -Wl,--export-dynamic -L. ./.libs/libgstreamer-1.0.so -L/usr/arm-linux-gnueabihf/lib -lgio-2.0 -lgobject-2.0 -lgmodule-2.0 -lgthread-2.0 -lrt -lglib-2.0 -pthread -Wl,-rpath -Wl,/usr/lib/arm-linux-gnueabihf /home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/Gst-1.0: line 117: /home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/.libs/lt-Gst-1.0: cannot execute binary file /home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/Gst-1.0: line 117: /home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/.libs/lt-Gst-1.0: Success Command '['/home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/Gst-1.0', '--introspect-dump=/home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/functions.txt,/home/build/src/gstreamer1.0/gst/tmp-introspecteM6YUf/dump.xml']' returned non-zero exit status 126 make[5]: *** [Gst-1.0.gir] Error 1 ( please find full trace attached) xdeb -a armhf --only-explicit --no-lintian --apt-source gstreamer1.0-plugins-base Fails: ... ===== Importing keyutils_1.5.5-3 ===== apt-get -oAPT::Architecture=armhf download keyutils:armhf Get:1 Downloading keyutils 1.5.5-3 [30.3 kB] Fetched 30.3 kB in 0s (55.9 kB/s) apt-get -oAPT::Architecture=armhf download keyutils-dbg:armhf Get:1 Downloading keyutils-dbg 1.5.5-3 [57.2 kB] Fetched 57.2 kB in 0s (437 kB/s) apt-get -oAPT::Architecture=armhf download libkeyutils1:armhf Get:1 Downloading libkeyutils1 1.5.5-3 [6626 B] Fetched 6626 B in 0s (19.9 kB/s) apt-get -oAPT::Architecture=armhf download libkeyutils-dev:armhf Get:1 Downloading libkeyutils-dev 1.5.5-3 [25.8 kB] Fetched 25.8 kB in 0s (94.9 kB/s) Traceback (most recent call last): File "/usr/bin/xdeb", line 988, in <module> main() File "/usr/bin/xdeb", line 973, in main native_import(options, src) File "/usr/bin/xdeb", line 585, in native_import crossed_debs = cross_convert(options, debs, options.builddirs[0]) File "/usr/bin/xdeb", line 484, in cross_convert deb)).debcontrol() File "/usr/lib/python2.7/dist-packages/debian/debfile.py", line 271, in __init__ compressed_part_name(DATA_PART))) File "/usr/lib/python2.7/dist-packages/debian/debfile.py", line 256, in compressed_part_name " (expected one of: %s)" % candidates) debian.debfile.DebError: missing required part in given .deb (expected one of: ['data.tar.gz', 'data.tar.bz2', 'data.tar.lzma']) I have tried to use repo quantal-updates with also bad result. I have tried to use lower level tools, but I did not found a way to install cross build-deps apt-get build-dep -aarmhf ... always fails like this: sudo apt-get -oAPT::Architecture=armhf build-dep gstreamer1.0 [sudo] password for build: Reading package lists... Done Building dependency tree Reading state information... Done The following packages have unmet dependencies: build-essential : Depends: dpkg-dev (>= 1.13.5) but it is not going to be installed cdbs : Depends: dh-translations but it is not going to be installed debhelper : Depends: dpkg-dev (>= 1.16.2) but it is not going to be installed docbook-utils : Depends: docbook-dsssl but it is not going to be installed Depends: jadetex but it is not going to be installed gnome-pkg-tools : Depends: dh-translations but it is not going to be installed gtk-doc-tools : Depends: docbook-dsssl but it is not going to be installed Depends: docbook-xml (>= 4.3) but it is not going to be installed Depends: docbook-xsl (>= 1.64.1.0) but it is not going to be installed Depends: docbook-to-man but it is not going to be installed Depends: gnome-common but it is not going to be installed transfig : Depends: x11-common but it is not going to be installed xmlto : Depends: docbook-xml (>= 4.2-8) but it is not going to be installed Depends: docbook-xsl (>= 1.64.1.0) but it is not going to be installed E: Build-dependencies for gstreamer1.0 could not be satisfied. I guess I missed something... apt.conf ? sources.list... ? Can somebody help me ? best regards, pascal

11 years

Re: Samsung topic for 13.03

by Tushar Behera

> Looks like the ll-20130320.0 kernel failed to boot on Arndale: > http://validation.linaro.org/lava-server/scheduler/job/49985/log_file > > The build log is here: > https://ci.linaro.org/jenkins/job/linux-linaro-tracking_arndale/62/consoleF… > > > The kernel config has been made by the following command: > 'ARCH=arm scripts/kconfig/merge_config.sh > linaro/configs/linaro-base.conf linaro/configs/ubuntu-minimal.conf > linaro/configs/arndale.conf linaro/configs/kvm-host.conf' > > Tushar, > Have you tried this configuration? > > Thanks, > Andrey I have been observing this system hang when we enable LPAE on 3.9 based llct, though the issue is not present with vanilla 3.9-rc kernel. Would update later after I debug further. Riku, How much essential is it to enable LPAE support for KVM? -- Tushar Behera

11 years

Re: BLS 13.03 RC1 ready for testing

by Dietmar Eggemann

Hi Viresh, (1) Recently I have done a lot of testing for the new RCU functionality (new RCU FNOHZ implementation, updated RCU no-callback implementation) which is scheduled for 3.11/3.12 mainline. In my tests it helped to keep the A15's quiet and showed power savings for some workloads. During last Linaro Connect people started to ask me if we can bring these features in already earlier. Would it be possible for you to merge in 'idlenocb.2013.03.18b' (based on v3.9-rc2) (or newer) from 'git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git' into your big.LITTLE MP tree? I talked to Paul McKenney about this and he would like to have this additional test coverage. I have performed the following tests: System comes up and pm-qa (cpufreq, cpuidle, cpuhotplug) on nano and FTS (mpbasic, mpcore, mpextended, mploadbalance, mpregression, pmump) on Android FS look good. (2) On top of the merge, we must assure that the TC2 default config file gets changed: Change the config file: * Set CONFIG_RCU_FAST_NO_HZ=y * Set CONFIG_RCU_NOCB_CPU=y * Set CONFIG_RCU_NOCB_CPU_ALL=y diff -Naur config_orig .config --- config_orig 2013-03-13 14:15:10.574248125 +0000 +++ .config 2013-03-13 14:15:34.334248346 +0000 @@ -93,9 +93,12 @@ CONFIG_RCU_FANOUT=32 CONFIG_RCU_FANOUT_LEAF=16 # CONFIG_RCU_FANOUT_EXACT is not set -# CONFIG_RCU_FAST_NO_HZ is not set +CONFIG_RCU_FAST_NO_HZ=y # CONFIG_TREE_RCU_TRACE is not set -# CONFIG_RCU_NOCB_CPU is not set +CONFIG_RCU_NOCB_CPU=y +# CONFIG_RCU_NOCB_CPU_NONE is not set +# CONFIG_RCU_NOCB_CPU_ZERO is not set +CONFIG_RCU_NOCB_CPU_ALL=y CONFIG_IKCONFIG=y CONFIG_IKCONFIG_PROC=y CONFIG_LOG_BUF_SHIFT=16 Cheers, -- Dietmar -- IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

11 years

[PATCH v3 0/5] common clk framework reentrancy & dvfs, take 3

by Mike Turquette

Hello, This series implements reentrancy for the common clk implementation of the clk.h api. Making reentrant calls into the clock framework is both necessary and desirable for many use cases such as enabling off-chip clocks via i2c. The first patch in the series implements this. A neat side effect of reentrancy is that it is possible for platforms using voltage regulators controlled via i2c to register rate-change notifier handlers to scale voltage as a function of clock rate. This is an effective way to implement dynamic voltage & frequency scaling. Patch #2 implements a helper function for registering such a notifier handler. The third patch in the series demonstrates dvfs on OMAP platforms by modifying the cpufreq-omap driver; it migrates the voltage scaling logic out of the cpufreq driver's .target callback and registers callbacks via the helper introduced in patch #2. Patches four and five are purely test coverage. And what better way to test than to muck with fragile PLL programming code? These patches test out a lot of the aforementioned reentrancy in the OMAP3+ DPLL code. They are not for merging, but as a demonstration of what is now possible. Finally, I know that Documentation/clk.txt needs an update for these changes but I wanted this on the list before I flew out to LCA 2013. I'll provide that update during or after the conference. Two previous (and considerably more insane) attempts at this, v1: http://article.gmane.org/gmane.linux.kernel/1327866 v2: http://marc.info/?l=linux-kernel&m=134507429302463&w=2 Mike Turquette (5): clk: allow reentrant calls into the clk framework clk: notifier handler for dynamic voltage scaling cpufreq: omap: scale regulator from clk notifier HACK: set_parent callback for OMAP4 non-core DPLLs HACK: omap: opp: add fake 400MHz OPP to bypass MPU arch/arm/mach-omap2/cclock44xx_data.c | 1 + arch/arm/mach-omap2/clock.h | 1 + arch/arm/mach-omap2/dpll3xxx.c | 107 ++++++++++---- arch/arm/mach-omap2/opp4xxx_data.c | 18 +++ drivers/clk/Makefile | 1 + drivers/clk/clk.c | 254 ++++++++++++++++++++++++--------- drivers/clk/dvfs.c | 125 ++++++++++++++++ drivers/cpufreq/omap-cpufreq.c | 82 +++-------- include/linux/clk.h | 27 +++- 9 files changed, 459 insertions(+), 157 deletions(-) create mode 100644 drivers/clk/dvfs.c -- 1.7.10.4

11 years

API to download from snapshots and releases is live

by James Tunnicliffe

Hi, There are many scripts in use that parse the web interface for snapshots and releases.linaro.org. This is far from ideal because changes to the web interface can result in the scripts breaking. To alleviate this problem an API has been introduced. The API is very simple, just two new URLs and a new header when downloading files. <server>/api/ls/<path to file> returns a JSON document containing all the data shown by a file listing on the web interface. It can target either a directory of a file. <server>/api/license/<path to file> returns a JSON document containing the licence information for the file pointed to. Both the license text and the digest used to accept the license are returned. Including the digest means that the choice of digest used internally can change without re-writing clients - to the client this is just a magic string and they don't need to care how it is generated. When downloading a file you simply include the header LICENSE_ACCEPTED, its value being a space separated list of license digests representing the licenses that you have accepted. e.g. (license text and digest removed for brevity) http://snapshots.linaro.org/api/ls/quantal/hwpacks/snowball/latest { "files": [ { "mtime": "15-Mar-2013 08:29", "name": "hwpack_linaro-snowball_20130315-269_armhf_supported.manifest.txt", "size": "762", "type": "text", "url": "/quantal/hwpacks/snowball/latest/hwpack_linaro-snowball_20130315-269_armhf_supported.manifest.txt" }, { "mtime": "15-Mar-2013 08:31", "name": "hwpack_linaro-snowball_20130315-269_armhf_supported.tar.gz", "size": "18.1M", "type": "other", "url": "/quantal/hwpacks/snowball/latest/hwpack_linaro-snowball_20130315-269_armhf_supported.tar.gz" } ] } http://snapshots.linaro.org/api/license/quantal/hwpacks/snowball/latest/hwp… { "licenses": [ { "text": "license text...", "digest": "license digest..." } ] } wget --header="LICENSE_ACCEPTED: license digest..." http://snapshots.linaro.org/quantal/hwpacks/snowball/latest/hwpack_linaro-s… There is a example client script that illustrates how to use the API here: http://bazaar.launchpad.net/~linaro-automation/linaro-license-protection/tr… Usage: download.py <URL> If URL points to a directory all files are downloaded. If URL points to a file, just that file is downloaded. It prints the license(s) for each file and waits for the user to accept each one. It also stores which licenses the user has accepted so they don't need to be re-accepted if the text hasn't changed. -- James Tunnicliffe

11 years

[PATCH 1/1] clk: Add notifier support in clk_prepare/clk_unprepare

by Bill Huang

Add notifier calls in clk_prepare and clk_unprepare so drivers which are interested in knowing that clk_prepare/unprepare call can act accordingly. The existing "clk_set_rate" notifier is not enough for normal DVFS inplementation since clock might be enabled/disabled at runtime. Adding these notifiers is useful on DVFS core which take clk_prepare as a hint on that the notified clock might be enabled later so it can raise voltage to a safe level before enabling the clock, and take clk_unprepare as a hint that the clock has been disabled and is safe to lower the voltage. The added notifier events are: PRE_CLK_PREPARE POST_CLK_PREPARE ABORT_CLK_PREPARE PRE_CLK_UNPREPARE POST_CLK_UNPREPARE Signed-off-by: Bill Huang <bilhuang(a)nvidia.com> --- drivers/clk/clk.c | 88 ++++++++++++++++++++++++++++++--------------------- include/linux/clk.h | 5 +++ 2 files changed, 57 insertions(+), 36 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index ed87b24..ac07c6e 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -516,6 +516,42 @@ struct clk *__clk_lookup(const char *name) /*** clk api ***/ +/** + * __clk_notify - call clk notifier chain + * @clk: struct clk * that is changing rate + * @msg: clk notifier type (see include/linux/clk.h) + * @old_rate: old clk rate + * @new_rate: new clk rate + * + * Triggers a notifier call chain on the clk rate-change notification + * for 'clk'. Passes a pointer to the struct clk and the previous + * and current rates to the notifier callback. Intended to be called by + * internal clock code only. Returns NOTIFY_DONE from the last driver + * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if + * a driver returns that. + */ +static int __clk_notify(struct clk *clk, unsigned long msg, + unsigned long old_rate, unsigned long new_rate) +{ + struct clk_notifier *cn; + struct clk_notifier_data cnd; + int ret = NOTIFY_DONE; + + cnd.clk = clk; + cnd.old_rate = old_rate; + cnd.new_rate = new_rate; + + list_for_each_entry(cn, &clk_notifier_list, node) { + if (cn->clk == clk) { + ret = srcu_notifier_call_chain(&cn->notifier_head, msg, + &cnd); + break; + } + } + + return ret; +} + void __clk_unprepare(struct clk *clk) { if (!clk) @@ -549,7 +585,14 @@ void __clk_unprepare(struct clk *clk) void clk_unprepare(struct clk *clk) { mutex_lock(&prepare_lock); + + if (clk->notifier_count) + __clk_notify(clk, PRE_CLK_UNPREPARE, clk->rate, clk->rate); + __clk_unprepare(clk); + if (clk->notifier_count) + __clk_notify(clk, POST_CLK_UNPREPARE, clk->rate, clk->rate); + mutex_unlock(&prepare_lock); } EXPORT_SYMBOL_GPL(clk_unprepare); @@ -597,7 +640,16 @@ int clk_prepare(struct clk *clk) int ret; mutex_lock(&prepare_lock); + + if (clk->notifier_count) + __clk_notify(clk, PRE_CLK_PREPARE, clk->rate, clk->rate); + ret = __clk_prepare(clk); + if (!ret && clk->notifier_count) + __clk_notify(clk, POST_CLK_PREPARE, clk->rate, clk->rate); + else if (clk->notifier_count) + __clk_notify(clk, ABORT_CLK_PREPARE, clk->rate, clk->rate); + mutex_unlock(&prepare_lock); return ret; @@ -749,42 +801,6 @@ long clk_round_rate(struct clk *clk, unsigned long rate) EXPORT_SYMBOL_GPL(clk_round_rate); /** - * __clk_notify - call clk notifier chain - * @clk: struct clk * that is changing rate - * @msg: clk notifier type (see include/linux/clk.h) - * @old_rate: old clk rate - * @new_rate: new clk rate - * - * Triggers a notifier call chain on the clk rate-change notification - * for 'clk'. Passes a pointer to the struct clk and the previous - * and current rates to the notifier callback. Intended to be called by - * internal clock code only. Returns NOTIFY_DONE from the last driver - * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if - * a driver returns that. - */ -static int __clk_notify(struct clk *clk, unsigned long msg, - unsigned long old_rate, unsigned long new_rate) -{ - struct clk_notifier *cn; - struct clk_notifier_data cnd; - int ret = NOTIFY_DONE; - - cnd.clk = clk; - cnd.old_rate = old_rate; - cnd.new_rate = new_rate; - - list_for_each_entry(cn, &clk_notifier_list, node) { - if (cn->clk == clk) { - ret = srcu_notifier_call_chain(&cn->notifier_head, msg, - &cnd); - break; - } - } - - return ret; -} - -/** * __clk_recalc_rates * @clk: first clk in the subtree * @msg: notification type (see include/linux/clk.h) diff --git a/include/linux/clk.h b/include/linux/clk.h index b3ac22d..41d567d 100644 --- a/include/linux/clk.h +++ b/include/linux/clk.h @@ -43,6 +43,11 @@ struct clk; #define PRE_RATE_CHANGE BIT(0) #define POST_RATE_CHANGE BIT(1) #define ABORT_RATE_CHANGE BIT(2) +#define PRE_CLK_PREPARE BIT(3) +#define POST_CLK_PREPARE BIT(4) +#define ABORT_CLK_PREPARE BIT(5) +#define PRE_CLK_UNPREPARE BIT(6) +#define POST_CLK_UNPREPARE BIT(7) /** * struct clk_notifier - associate a clk with a notifier -- 1.7.9.5

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linaro-dev March 2013