On Thu, Oct 10, 2013 at 3:22 PM, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: > On 10/10/2013 02:58 PM, Alexandre Courbot wrote: >> On Wed, Oct 9, 2013 at 4:47 PM, Olof Johansson <olof@xxxxxxxxx> wrote: >>> On Fri, Oct 4, 2013 at 9:37 AM, Alexandre Courbot <acourbot@xxxxxxxxxx> wrote: > ... >>> But do we really need to panic here? It's a PITA to debug since it'll >>> be a very early panic. I'd rather have the system log errors in dmesg >>> but continue booting with one cpu. >> >> Actually the first version of this series continued on one CPU if TF >> support was missing (as secondary CPUs would simply fail to boot), but >> IIRC Stephen advocated for the current behavior (panic) instead. I >> agree such an early panic is hard to debug, especially considering >> that most devices using TF (Tegra retail devices) do not even feature >> a serial port. >> >> On the other hand, if we continue booting in these conditions the >> system freezes as soon as cpuidle kicks in, so we won't be going very >> far anyway. However the console is up when it happens. >> >> Maybe if there is a way to disable the kernel features TF is supposed >> to manage (SMP & cpuidle at the moment) when registration fails, the >> system could continue more gracefully (even if on one leg) and warn >> the user about this condition. Stephen, can I have your thoughts on >> this? > > If we can disable the features that rely on TF/secure-mode when support > is missing, then doing that rather than panic is fine. We do something > similar for PCIe on Tegra20, where LP2 cpuidle state must be disabled or > PCIe interrupts won't work. > > I would be inclined to merge the patch as-is right now, since it's only > enabling a new feature that won't see any regressions due to this panic, > and then add the disable-other-features with a separate patch/series > later. Does that seem reasonable? Yes, I tried to make that clear with my initial feedback: I think it would be good to get away from the panic, but we can merge with it now and fix it with later patches. -Olof -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
