[PATCH] ARM: samsung: avoid racy early printk at bootup

Doug Anderson dianders at chromium.org
Wed Jun 5 16:56:52 EDT 2013


Olof,

On Tue, Jun 4, 2013 at 8:15 PM, Olof Johansson <olof at lixom.net> wrote:
> This seems to be caused by not calling iotable_ini() in exynos_init_io()
> when a device tree is passed into the kernel, thus not setting up the
> mapping for the UART in that case.
>
> I think the solution is instead to map the uart earlier. The window of
> exposure is still there, but much smaller (and similar to how it always
> has been).
>
> In current upstream, if there is no map_io mach_desc entry at all,
> debug_ll_io_init() will be called on all platforms. Seems appropriate
> to call that explicitly before of_scan_flat_dt() in exynos_init_io()
> in this case.

Oh.  Ummm, right.  Yes, debug_ll_io_init() is exactly what's needed
here instead of all the complexity of what I proposed.  New patch
coming shortly.  Thanks!  :)

-Doug



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