[PATCH 01/34] cpufreq: move freq change notifications to cpufreq core
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: 2013-08-16 02:26:04
Also in:
linux-arm-kernel, lkml, sparclinux
Subsystem:
cpu frequency scaling framework, the rest · Maintainers:
"Rafael J. Wysocki", Viresh Kumar, Linus Torvalds
Most of the drivers do following in their ->target_index() routines: struct cpufreq_freqs freqs; freqs.old = old freq... freqs.new = new freq... cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE); /* Change rate here */ cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE); This is replicated over all cpufreq drivers today and there doesn't exists a good enough reason why this shouldn't be moved to cpufreq core instead. There are few special cases though, like exynos5440, which doesn't do everything on the call to ->target_index() routine and call some kind of bottom halves for doing this work, work/tasklet/etc.. They may continue doing notification from their own code and so this patch introduces another flag: CPUFREQ_NO_NOTIFICATION, which will be set by such drivers. Cc: Andrew Lunn <andrew@lunn.ch> Cc: David S. Miller <davem@davemloft.net> Cc: Dmitry Eremin-Solenikov <redacted> Cc: Eric Miao <redacted> Cc: Hans-Christian Egtvedt <redacted> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: John Crispin <redacted> Cc: Kukjin Kim <redacted> Cc: Linus Walleij <redacted> Cc: linux-cris-kernel@axis.com Cc: Mikael Starvik <redacted> Cc: Russell King <redacted> Cc: Santosh Shilimkar <redacted> Cc: Sekhar Nori <redacted> Cc: Shawn Guo <redacted> Cc: sparclinux@vger.kernel.org Cc: spear-devel@list.st.com Cc: Stephen Warren <redacted> Cc: Steven Miao <redacted> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/cpufreq/cpufreq.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/cpufreq.h | 6 ++++++ 2 files changed, 40 insertions(+)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index a7a1d3e..2782949 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c@@ -1673,6 +1673,9 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy, retval = cpufreq_driver->target(policy, target_freq, relation); else if (cpufreq_driver->target_index) { struct cpufreq_frequency_table *freq_table; + struct cpufreq_freqs freqs; + unsigned long flags; + bool notify; int index; freq_table = cpufreq_frequency_get_table(policy->cpu);
@@ -1691,7 +1694,38 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy, if (freq_table[index].frequency == policy->cur) return 0; + read_lock_irqsave(&cpufreq_driver_lock, flags); + notify = !(cpufreq_driver->flags | CPUFREQ_NO_NOTIFICATION); + read_unlock_irqrestore(&cpufreq_driver_lock, flags); + + if (notify) { + freqs.old = policy->cur; + freqs.new = freq_table[index].frequency; + + pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", + __func__, policy->cpu, freqs.old, + freqs.new); + + cpufreq_notify_transition(policy, &freqs, + CPUFREQ_PRECHANGE); + } + retval = cpufreq_driver->target_index(policy, index); + if (retval) + pr_err("%s: Failed to change cpu frequency: %d\n", + __func__, retval); + + if (notify) { + /* + * Notify with old freq in case we failed to change + * frequency + */ + if (retval) + freqs.new = freqs.old; + + cpufreq_notify_transition(policy, &freqs, + CPUFREQ_POSTCHANGE); + } } return retval;
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index ff9c8df..62ce478 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h@@ -221,6 +221,12 @@ struct cpufreq_driver { * frequency transitions */ #define CPUFREQ_PM_NO_WARN 0x04 /* don't warn on suspend/resume speed * mismatches */ +/* + * Driver will call cpufreq_notify_transition() in its target_index() routine + * and so cpufreq core must not call it. Only useful for drivers that implement + * target_index(), unused otherwise. + */ +#define CPUFREQ_NO_NOTIFICATION 0x08 int cpufreq_register_driver(struct cpufreq_driver *driver_data); int cpufreq_unregister_driver(struct cpufreq_driver *driver_data);
--
1.7.12.rc2.18.g61b472e