From mboxrd@z Thu Jan 1 00:00:00 1970 From: soren.brinkmann@xilinx.com (=?utf-8?B?U8O2cmVu?= Brinkmann) Date: Fri, 16 Aug 2013 10:28:38 -0700 Subject: Enable arm_global_timer for Zynq brakes boot In-Reply-To: <5209152F.5020307@linaro.org> References: <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> <5209152F.5020307@linaro.org> Message-ID: <86b18b0d-08e1-4899-86ea-ed22d3d36dee@DB8EHSMHS028.ehs.local> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Aug 12, 2013 at 07:02:39PM +0200, Daniel Lezcano wrote: > 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. Just to check in. Do you want any additional testing done? Or can I expect Stephens fix to get merged, so Zynq can use the GT? Thanks, S?ren