On Tue, Dec 12, 2017 at 01:24:52PM -0800, Kevin Hilman wrote:

On Tue, Dec 12, 2017 at 9:26 AM, Priit Laes [off-list ref] wrote:

quoted

On Mon, Dec 11, 2017 at 02:22:30PM -0800, Kevin Hilman wrote:

quoted

On Sun, Mar 26, 2017 at 10:20 AM, Priit Laes [off-list ref] wrote:

quoted

Convert sun4i-a10.dtsi to new CCU driver.

Signed-off-by: Priit Laes <plaes-q/aMd4JkU83YtjvyW6yDsg@public.gmane.org>

I finally got around to bisecting a mainline boot failure on
sun4i-a10-cubieboard that's been happening for quite a while.  Based
on on kernelci.org, it showed up sometime during the v4.15 merge
window[1].  It bisected down to this commit (in mainline as commit
41193869f2bdb585ce09bfdd16d9482aadd560ad).

When it fails, there is no output on the serial console, so I don't
know exactly how it's failing, just that it no longer boots.

We tried out latest 4.15 with various compilers and it works:
- gcc version 7.1.1 20170622 (Red Hat Cross 7.1.1-3) (GCC) - A10 Gemei G9 tablet
- gcc 7.2.0-debian - A10 Cubieboard

And you can reproduce the bug with gcc5 or gcc6?

Very strange that a DT only patch would cause a gcc related regression
and if it does, it should be investigated.  I don't think requiring
gcc7 is an appropriate solution.

@Chen-Yu, @Maxime: are you guys OK with requiring gcc7 for working
upstream boot for A10?

I'd rather not set that kind of constraints and fix the issue instead.

Priit, can you test with an older compiler?
You can find one here:
http://toolchains.free-electrons.com/

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com