On Thu, Jan 7, 2021 at 2:37 PM Russell King - ARM Linux admin
[off-list ref] wrote:

On Thu, Jan 07, 2021 at 02:16:25PM +0100, Arnd Bergmann wrote:

quoted

On Thu, Jan 7, 2021 at 1:47 PM Russell King - ARM Linux admin
[off-list ref] wrote:

quoted

The gcc bugzilla mentions backports into gcc-linaro, but I do not see
them in my git history.

Correction: I looked in the wrong branch, gcc-linaro does have it, as
does the Android gcc, which was recently still at 4.9 before they dropped it
in favor of clang.

So, do we raise the minimum gcc version for the kernel as a whole to 5.1
or just for aarch64?

I'd personally love to see gcc-5 as the global minimum version, as that
would let us finally use --std=gnu11 features instead of gnu89. [There are
a couple of useful features that are incompatible with gnu89, and
gnu99/gnu11 support in gcc didn't like the kernel sources]

If we make it arm64 specific, I'd propose only making it a build-time
warning instead of an error, as there are no other benefits to increasing
the minimum version if gcc-4.9 is still an option for other architectures,
and most gcc-4.9 users (Android, Red Hat and everyone using gcc-linaro)
have backported this bugfix already.

         Arnd