On Tue, Mar 14, 2017 at 9:52 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Tue, Mar 14, 2017 at 5:17 PM, Masahiro Yamada > <yamada.masahiro@xxxxxxxxxxxxx> wrote: >> Hi Arnd, >> >> 2017-01-14 0:40 GMT+09:00 Arnd Bergmann <arnd@xxxxxxxx>: >>> In commit a76bcf557ef4 ("Kbuild: enable -Wmaybe-uninitialized warning >>> for "make W=1""), I reverted another change that happened to fix a problem >>> with old compilers, and now we get this report again with old compilers >>> (prior to gcc-4.8) and GCOV enabled: >>> >>> cc1: warnings being treated as errors >>> drivers/gpu/drm/i915/intel_ringbuffer.c: In function 'intel_ring_setup_status_page': >>> drivers/gpu/drm/i915/intel_ringbuffer.c:438: error: 'mmio.reg' may be used uninitialized in this function >>> At top level: >>>>> cc1: error: unrecognized command line option "-Wno-maybe-uninitialized" >>> >>> The problem is that we turn off the warning conditionally in a number >>> of places as we should, but one of them does it unconditionally. >>> Instead, change it to call cc-disable-warning as we do elsewhere. >>> >>> The original patch that caused it was merged into linux-4.7, then >>> 4.8 removed the change and 4.9 brought it back, so we probably want >>> a backport to 4.9 once this is merged. >>> >>> Cc: stable@xxxxxxxxxxxxxxx >>> Fixes: a76bcf557ef4 ("Kbuild: enable -Wmaybe-uninitialized warning for "make W=1"") >>> Fixes: e72e2dfe7c16 ("gcov: disable -Wmaybe-uninitialized warning") >>> Reported-by: kbuild test robot <fengguang.wu@xxxxxxxxx> >>> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> >> >> >> Applied to linux-kbuild/fixes. Hmm, after I've carried this patch for months, I now found that it caused a build time regression. I'm sending a fix for that too, please either apply the fix on top, or fold it into the first patch. Arnd