On Tuesday 28 October 2014 14:05:36 Russell King - ARM Linux wrote: > On Tue, Oct 28, 2014 at 09:31:35PM +0800, Xia Kaixu wrote: > > The early debug could break something when booting 'allmodconfig' > > kernels. So we use early console instead of early debug. > > > > The early console didn't work yet on OMAP4460 because of missing > > earlycon support and I am working on that. > > No. bloody. way. > > > @@ -78,7 +78,7 @@ config DEBUG_USER > > # These options are only for real kernel hackers who want to get their > > hands dirty. > > config DEBUG_LL > > bool "Kernel low-level debugging functions (read help!)" > > - depends on DEBUG_KERNEL > > + depends on DEBUG_KERNEL && !ARCH_MULTIPLATFORM_STRICT > > Firstly, this is well advertised that it can only be applied to a single > configuration. So I don't think we need this dependency here. Even if > you want to build a strict multiplatform kernel, it should still be > possible to enable this for a specific platform.
I've asked Kaixu to do this patch. This is one of the most fundamental uses of ARCH_MULTIPLATFORM_STRICT: as soon as you turn on DEBUG_LL, the kernel no longer runs on any other platform, so it can still be built as a multiplatform kernel, but not a "strict" one that is known to work on all hardware that is enabled. > It's a developer option, one which requires the developer to engage their > brain before using. Exactly, and I think it's not asking too much from a developer to turn off ARCH_MULTIPLATFORM_STRICT if they want to turn on DEBUG_LL. Nothing else should change if you do that. The main use of the symbol is really to avoid turning on DEBUG_LL is allmodconfig kernels, which will always enable ARCH_MULTIPLATFORM_STRICT. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/