On Sat, Jun 29, 2013 at 03:07:38AM +0100, Stephen Boyd wrote: > On 06/28, Stephen Boyd wrote: > > On 06/28/13 09:58, Stehle Vincent-B46079 wrote: > > > From: linux-next-owner@xxxxxxxxxxxxxxx [mailto:linux-next-owner@xxxxxxxxxxxxxxx] On Behalf Of Stephen Boyd > > > (..) > > >> Do you have debug_ll support to get some serial logs? > > > Hi, > > > > > > Thanks for your concern on the matter. You are right, there is debug_ll support for i.MX6. If I activate it for next-20130628 imx_v6_v7_defconfig, that only "buys" me one additional line, though: > > > > > > Uncompressing Linux... done, booting the kernel. > > > > Oh and also add earlyprintk to the command line and enable the > > earlyprintk config. It should buy you some more lines. > > > > > > > >> Also could you try booting with maxcpus=1 on the kernel commandline? > > > Good idea; it goes much further with this one (until it crashes in wm8962_probe(), which is as far as I go when I revert 064706514ec3fea740c2656e03c4f01f6a551ac4). > > > > Interesting. Thanks for the test. > > > > > > > >> And it would be useful to have the output of /proc/timer_list if you have it from a working device. > > > Sure; I pasted it below. > > > > Is this an SMP capable device? What devicetree blob are you using? > > > > > > > >> I believe you have a per-cpu TWD timer and a global imx-gpt? > > > I think you are right from what I see in /proc/interrupts. > > > > Well oddly I don't see any twd in the timer list but that may be because > > you're not running more than one CPU? It would be good to get the output > > when you run SMP if it has that support. > > > > I tried to recreate this probelm an an smp vexpress qemu and I > couldn't do it. This is with next-20130628. If you can get > debug_ll and earlyprinkt working it would be useful if you can > apply the attached patch and give back the logs. I'm confused how > the dummy timers are causing problems. Similarly I couldn't reproduce the issue on a physical A9x4 coretile with next-20130627. In case there's some weird interaction with the imx-gpt registration, I tried dropping the rating on the sp804 down to 200 to match, and also removed CLOCKEVT_FEAT_PERIODIC from its features, but was still able to get to userspace. If I've followed the code correctly, I see mxc_timer_init is called from the imx6q_clocks_init, which is marked with CLK_OF_DECLARE. I had a suspicion that there was an ordering issue that we were somehow irritating, but given booting with one CPU worked, that doesn't seem to be the case. On me A9x4. I can't move the sp804 to CLK_OF_INIT to check as I cannot guarantee I'll have the requisite clocks. I'm also left scratching my head on this one. A dmesg and timer list from a working SMP boot would be useful. Thanks, Mark. > > diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c > index 9d96a54..3795c9c 100644 > --- a/kernel/time/tick-broadcast.c > +++ b/kernel/time/tick-broadcast.c > @@ -92,6 +92,8 @@ void tick_install_broadcast_device(struct clock_event_device *dev) > if (!try_module_get(dev->owner)) > return; > > + pr_info("%s is now the broadcast\n", dev->name); > + > clockevents_exchange_device(cur, dev); > if (cur) > cur->event_handler = clockevents_handle_noop; > diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c > index edd45f6..24548aa 100644 > --- a/kernel/time/tick-common.c > +++ b/kernel/time/tick-common.c > @@ -275,6 +275,8 @@ void tick_check_new_device(struct clock_event_device *newdev) > struct tick_device *td; > int cpu; > > + pr_info("Checking %s\n", newdev->name); > + > cpu = smp_processor_id(); > if (!cpumask_test_cpu(cpu, newdev->cpumask)) > goto out_bc; > @@ -286,10 +288,14 @@ void tick_check_new_device(struct clock_event_device *newdev) > if (!tick_check_percpu(curdev, newdev, cpu)) > goto out_bc; > > + pr_info("%d: %s is per-cpu\n", cpu, newdev->name); > + > /* Preference decision */ > if (!tick_check_preferred(curdev, newdev)) > goto out_bc; > > + pr_info("%d: %s is preferred\n", cpu, newdev->name); > + > if (!try_module_get(newdev->owner)) > return; > > @@ -312,6 +318,7 @@ out_bc: > /* > * Can the new device be used as a broadcast device ? > */ > + pr_info("%d: %s is trying broadcast\n", cpu, newdev->name); > tick_install_broadcast_device(newdev); > } > > > -- > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > hosted by The Linux Foundation > -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
