> -----Original Message----- > From: Russell King - ARM Linux [mailto:linux@xxxxxxxxxxxxxxxx] > Sent: Friday, June 24, 2011 4:22 PM > To: Premi, Sanjeev > Cc: linux-omap@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH 2/2] omap2+: pm: cpufreq: Fix > loops_per_jiffy calculation > > On Fri, Jun 24, 2011 at 04:18:31PM +0530, Premi, Sanjeev wrote: > > > -----Original Message----- > > > From: Russell King - ARM Linux [mailto:linux@xxxxxxxxxxxxxxxx] > > > Sent: Friday, June 24, 2011 4:14 PM > > > To: Premi, Sanjeev > > > Cc: linux-omap@xxxxxxxxxxxxxxx; > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > > > Subject: Re: [PATCH 2/2] omap2+: pm: cpufreq: Fix > > > loops_per_jiffy calculation > > > > > > On Fri, Jun 24, 2011 at 04:05:42PM +0530, Sanjeev Premi wrote: > > > > Currently, loops_per_jiffy is being calculated before calling > > > > cpufreq_notify_transition(). > > > > > > > > However, generic cpufreq driver adjusts the jiffies as well. > > > > Double adjustment leads to incorrect value being assigned to > > > > loops_per_jiffy. > > > > > > Are you sure the generic cpufreq driver adjusts the per-cpu > > > loops_per_jiffy > > > values? I don't believe it does. > > > > Russell, > > > > I am quoting the function from drivers/cpufreq/cpufreq.h > > Follow the arrows: > > Let's go to war with quotes then, because clearly you haven't > read the code > properly: [sp] Peace. No war! Looks like I missed the ifndef in systax highlighting on my editor. As mentioned, I couldn't test on OMAP4. The patch obvioulsy works for A8... SMP needs to be fixed. v2 coming soon. ~sanjeev > > | #ifndef CONFIG_SMP > ^^^^^^^^^^^^^^^^^^^^^ > | static unsigned long l_p_j_ref; > | static unsigned int l_p_j_ref_freq; > | > | static void adjust_jiffies(unsigned long val, struct > cpufreq_freqs *ci) > | { > | ... code to adjust jiffies ... > | } > | #else > | static inline void adjust_jiffies(unsigned long val, struct > cpufreq_freqs *ci) > | { > | return; > | } > | #endif > > Notice how if CONFIG_SMP is set, adjust_jiffies becomes a > no-op. So if > CONFIG_SMP=y, loops_per_jiffy will _not_ be scaled by core code. > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
