Re: [PATCH] drm/amd/display: Increase frame-larger-than warning limit

[Palmer Dabbelt]

On Mon, 03 Jun 2024 15:29:48 PDT (-0700), nathan@xxxxxxxxxx wrote:
> Hi Palmer,
>
> On Thu, May 30, 2024 at 07:57:42AM -0700, Palmer Dabbelt wrote:
> > From: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
> >
> > I get a handful of build errors along the lines of
> >
> >     linux/drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:58:13: error: stack frame size (2352) exceeds limit (2048) in 'DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndPerformanceCalculation' [-Werror,-Wframe-larger-than]
> >     static void DISPCLKDPPCLKDCFCLKDeepSleepPrefetchParametersWatermarksAndPerformanceCalculation(
> >                 ^
> >     linux/drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:1724:6: error: stack frame size (2096) exceeds limit (2048) in 'dml32_ModeSupportAndSystemConfigurationFull' [-Werror,-Wframe-larger-than]
> >     void dml32_ModeSupportAndSystemConfigurationFull(struct display_mode_lib *mode_lib)
> >          ^
>
> Judging from the message, this is clang/LLVM? What version?

Yes, LLVM.  Looks like I'm on 16.0.6.  Probably time for an update, so 
I'll give it a shot.

> I assume
> this showed up in 6.10-rc1 because of commit 77acc6b55ae4 ("riscv: add
> support for kernel-mode FPU"), which allows this driver to be built for
> RISC-V.

Seems reasonable.  This didn't show up until post-merge, not 100% sure 
why.  I didn't really dig any farther.

> Is this allmodconfig or some other configuration?

IIRC both "allmodconfig" and "allyesconfig" show it, but I don't have a 
build tree sitting around to be 100% sure.

> > as of 6.10-rc1.
> >
> > Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
> > ---
> >  drivers/gpu/drm/amd/display/dc/dml/Makefile | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/dc/dml/Makefile b/drivers/gpu/drm/amd/display/dc/dml/Makefile
> > index c4a5efd2dda5..b2bd72e63734 100644
> > --- a/drivers/gpu/drm/amd/display/dc/dml/Makefile
> > +++ b/drivers/gpu/drm/amd/display/dc/dml/Makefile
> > @@ -62,9 +62,9 @@ endif
> >
> >  ifneq ($(CONFIG_FRAME_WARN),0)
> >  ifeq ($(filter y,$(CONFIG_KASAN)$(CONFIG_KCSAN)),y)
> > -frame_warn_flag := -Wframe-larger-than=3072
> > +frame_warn_flag := -Wframe-larger-than=4096
> >  else
> > -frame_warn_flag := -Wframe-larger-than=2048
> > +frame_warn_flag := -Wframe-larger-than=3072
> >  endif
> >  endif
> >
> > --
> > 2.45.1