From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.lezcano@linaro.org (Daniel Lezcano) Date: Mon, 12 Aug 2013 19:02:39 +0200 Subject: Enable arm_global_timer for Zynq brakes boot In-Reply-To: <9b07d8a3-b650-4147-b952-9bcfc1172c51@VA3EHSMHS025.ehs.local> References: <1c83c081-60c6-49e3-a85c-f64dd5be0e60@CH1EHSMHS030.ehs.local> <51FA9F54.3060704@linaro.org> <5204C54A.9020105@st.com> <5204FA5D.3060908@linaro.org> <20130809172757.GD14845@codeaurora.org> <52090B43.9090000@codeaurora.org> <5209120D.1010701@linaro.org> <9b07d8a3-b650-4147-b952-9bcfc1172c51@VA3EHSMHS025.ehs.local> Message-ID: <5209152F.5020307@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 08/12/2013 06:53 PM, S?ren Brinkmann wrote: > On Mon, Aug 12, 2013 at 06:49:17PM +0200, Daniel Lezcano wrote: >> On 08/12/2013 06:32 PM, S?ren Brinkmann wrote: >>> On Mon, Aug 12, 2013 at 09:20:19AM -0700, Stephen Boyd wrote: >>>> On 08/12/13 09:03, S?ren Brinkmann wrote: >>>>> On Fri, Aug 09, 2013 at 10:27:57AM -0700, Stephen Boyd wrote: >>>>>> On 08/09, Daniel Lezcano wrote: >>>>>>> yes, but at least the broadcast mechanism should send an IPI to cpu0 to >>>>>>> wake it up, no ? As Stephen stated this kind of configuration should has >>>>>>> never been tested before so the tick broadcast code is not handling this >>>>>>> case properly IMHO. >>>>>>> >>>>>> If you have a per-cpu tick device that isn't suffering from >>>>>> FEAT_C3_STOP why wouldn't you use that for the tick versus a >>>>>> per-cpu tick device that has FEAT_C3_STOP? It sounds like there >>>>>> is a bug in the preference logic or you should boost the rating >>>>>> of the arm global timer above the twd. Does this patch help? It >>>>>> should make the arm global timer the tick device and whatever the >>>>>> cadence timer you have into the broadcast device. >>>>> I finally got to test your patch. Unfortunately, it makes the system >>>>> hang even earlier: >>>> >>>> Sorry it had a bug depending on the registration order. Can you try this >>>> one (tabs are probably spaces, sorry)? I will go read through this >>>> thread to see if we already covered the registration order. >>> >>> That did it! Booted straight into the system. >> >> Good news :) >> >>> The broadcast device is >>> the TTC instead of GT, now. >>> >>> Tick Device: mode: 1 >>> Broadcast device >>> Clock Event Device: ttc_clockevent >>> max_delta_ns: 1207932479 >>> min_delta_ns: 18432 >>> mult: 233015 >>> shift: 32 >>> mode: 1 >>> next_event: 9223372036854775807 nsecs >>> set_next_event: ttc_set_next_event >>> set_mode: ttc_set_mode >>> event_handler: tick_handle_oneshot_broadcast >>> retries: 0 >>> >>> tick_broadcast_mask: 00000000 >>> tick_broadcast_oneshot_mask: 00000000 >> >> At the first glance, the timer broadcast usage is not set, right ? Can >> you try with the cpuidle flag even if it is not needed ? > > It's actually present. I have a clean 3.11-rc3 and the only changes are > my patch to enable the GT and Stephen's fix. > The cpuidle stats show both idle states being used. Ah, right. The tick_broadcast_mask is not set because the arm global timer has not the CLOCK_EVT_FEAT_C3STOP feature flag set. Thanks -- Daniel -- Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog