> -----Original Message----- > From: Högander Jouni [mailto:jouni.hogander@xxxxxxxxx] > Sent: Monday, March 09, 2009 3:36 PM > To: Premi, Sanjeev > Cc: linux-omap@xxxxxxxxxxxxxxx > Subject: Re: Problems in cpuidle > > "ext Premi, Sanjeev" <premi@xxxxxx> writes: > > > While working with cpuidle, I have come across these problems. > > I am also working on the solutions, but would be good to hear more > > thoughts. > > > > 1) The flag 'enable_dyn_sleep' is honoured only in > omap3_idle_bm_check() > > but in the C1 state, omap3_enter_idle() is invoked directly. > > So, the system can transition to deeper idle state(s) > > > > Same is the case with 'sleep_block'. > > > > Possible Solutions: > > a) Call omap3_can_sleep() in omap3_enter_idle(). > > This makes omap3_idle_bm_check() redundant; and > can be removed. > > > > b) Make single entry point for all idle states > > But would be an overkill for C1 state. > > > > c) Change omap3_can_sleep() to check for omap_uart_can_sleep() > > and omap3_fclks_active() only. > > Move check for 'enable_dyn_sleep' and 'sleep_block' into > > omap3_enter_idle() > > > > I believe (c) would be the most optimal. > > Selecting (c) will break traditional pm_idle. Current plan is > to add one more C state (C1) which would prevent mpu/core > sleep transitions. Then remove fclk_active check completely. [sp] I meant doing the same for pm_idle as well. Also, the new cstate will not help with 'sleep' block. The proposed change look like: diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx index 7fc3cb3..c25158c 100644 --- a/arch/arm/mach-omap2/cpuidle34xx.c +++ b/arch/arm/mach-omap2/cpuidle34xx.c @@ -82,6 +82,11 @@ static int omap3_enter_idle(struct cpuidle_device *dev, /* Used to keep track of the total time in idle */ getnstimeofday(&ts_preidle); + if (!enable_dyn_sleep) + goto return_sleep_time; + if (atomic_read(&sleep_block) > 0) + goto return_sleep_time; + /* * Adjust the idle state (if required). * Also, ensure that usage statistics of correct state are updated. diff --git a/arch/arm/mach-omap2/pm34xx.c b/arch/arm/mach-omap2/pm34xx.c index 0716d60..5c7819a 100644 --- a/arch/arm/mach-omap2/pm34xx.c +++ b/arch/arm/mach-omap2/pm34xx.c @@ -476,14 +476,10 @@ static int omap3_fclks_active(void) int omap3_can_sleep(void) { - if (!enable_dyn_sleep) - return 0; if (!omap_uart_can_sleep()) return 0; if (omap3_fclks_active()) return 0; - if (atomic_read(&sleep_block) > 0) - return 0; return 1; } @@ -534,6 +530,11 @@ err: static void omap3_pm_idle(void) { + if (!enable_dyn_sleep) + return; + if (atomic_read(&sleep_block) > 0) + return; + local_irq_disable(); local_fiq_disable(); > > -- > Jouni Högander > > -- 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
