On 08/24/12 12:04, Jean Pihet wrote: > Hi Timo, > > On Fri, Aug 24, 2012 at 10:14 AM, Timo Kokkonen <timo.t.kokkonen@xxxxxx> wrote: >> Hi Jean, >> >> On 08/23/12 14:58, Jean Pihet wrote: >>> Hi Timo, >>> >>> On Wed, Aug 22, 2012 at 9:50 PM, Timo Kokkonen <timo.t.kokkonen@xxxxxx> wrote: >>> That is correct. The API to use is the PM QoS API which cpuidle uses >>> to determine the next MPU state based on the allowed latency. >>> >>>> A more appropriate fix for the problem would be to modify the idle >>>> layer so that it does not allow MPU going to too deep sleep modes when >>>> it is expected that the timers need to wake up MPU. >>> The idle layer already uses the PM QoS framework to decide the next >>> MPU state. I think the right solution is to convert from >>> omap_pm_set_max_mpu_wakeup_lat to the PM QoS API. >>> >>> Cf. http://marc.info/?l=linux-omap&m=133968658305580&w=2 for an >>> example of the conversion. >>> >> >> Thanks. It looks like really easy and straightforward conversion. >> However, I couldn't find the patch you were referring to from any trees > Correct, this patch is not applied to the mainline code yet, it is > provided as an example of the conversion. > >> I could find. So, I take that this API does not really have omap2 >> support in it yet? I tried git grepping through the source and to me it >> appears there is nothing in place yet that actually restricts the MPU >> sleep states on omap2 when requested. > The MPU state is controlled from the cpuidle framework, which > retrieves the MPU allowed latency from the PM QoS framework. This is > supported on OMAP2. > Cf. the table of states and the associated latency in > arch/arm/mach-omap2/cpuidle34xx.c. > Thanks for the pointer. I took a look at the state table and adjusted the latency requirements in my code. If I lower the latency from 50us to 10us, the timers are then waking up as they should be. I'll replace this patch with one where I convert it using the new API. Thanks! -Timo -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
