MyungJoo Ham wrote: > > On Wed, Nov 2, 2011 at 9:43 PM, Kukjin Kim <kgene.kim@xxxxxxxxxxx> wrote: > > From: Jongpill Lee <boyko.lee@xxxxxxxxxxx> > > > > This patch adds DVS lock feature for other driver and pm/ > > reboot notifier to enhance stability. > > (snip) > Same, following is from Jaecheol Lee. > Except for the case of PM (suspend/reset), it appears that this > feature is something that is meant to be supported by qos > (<linux/pm_qos.h>). > Couldn't we simply use the QoS feature to support locking frequency > above some specific levels? With QoS, I guess the implementation > becomes more general and straightforward. > Although we will probably need to use "CPU_DMA_LATENCY" for this case, > I think it isn't awefully difficult to use DMA-Latency as the metric. > Our goal is removal of using this cpufreq lock, but now some device driver which is not fully optimized need to use this lock temporary. If there is no request of this API from device driver, we will remove this feature or support this feature with different manner as you mentioned. > One concern about this is that we are hereby enforcing all the related > device drivers stuck with Exynos4210 only unless others also use > "cpufreq_lock_ID" and its friends. We recommend this feature in only rare instances (performance issue). After resolving that problem, the device driver which is using lock should be modified with removing lock. Actually, there is no device driver that using lock now. Thanks. Best regards, Kgene. -- Kukjin Kim <kgene.kim@xxxxxxxxxxx>, Senior Engineer, SW Solution Development Team, Samsung Electronics Co., Ltd. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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