Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
MIME-Version: 1.0
References: <20230717222923.3026018-1-samuel.holland@sifive.com> <20230718163953.GA1279879@dev-arch.thelio-3990X>
In-Reply-To: <20230718163953.GA1279879@dev-arch.thelio-3990X>
From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Wed, 19 Jul 2023 08:54:34 -0400
Message-ID: <CADnq5_N5raOvG+seU7MK2jXT5HVk1Wfp+m6yswQiOqdMpnVHAg@mail.gmail.com>
Subject: Re: [PATCH] drm/amd/display: Allow building DC with clang on RISC-V
To:     Nathan Chancellor <nathan@kernel.org>
Cc:     Samuel Holland <samuel.holland@sifive.com>,
        Nick Desaulniers <ndesaulniers@google.com>,
        llvm@lists.linux.dev, Leo Li <sunpeng.li@amd.com>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>,
        Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>,
        linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org,
        dri-devel@lists.freedesktop.org, Tom Rix <trix@redhat.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Applied.  Thanks!

On Tue, Jul 18, 2023 at 12:40=E2=80=AFPM Nathan Chancellor <nathan@kernel.o=
rg> wrote:
>
> On Mon, Jul 17, 2023 at 03:29:23PM -0700, Samuel Holland wrote:
> > clang on RISC-V appears to be unaffected by the bug causing excessive
> > stack usage in calculate_bandwidth(). clang 16 with -fstack-usage
> > reports a 304 byte stack frame size with CONFIG_ARCH_RV32I, and 512
> > bytes with CONFIG_ARCH_RV64I.
> >
> > Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
>
> I built ARCH=3Driscv allmodconfig drivers/gpu/drm/amd/amdgpu/ (confirming
> that CONFIG_DRM_AMD_DC gets enabled) with LLVM 11 through 17 with and
> without CONFIG_KASAN=3Dy and I never saw the -Wframe-larger-than instance
> that this was disabled for, so I agree.
>
> Reviewed-by: Nathan Chancellor <nathan@kernel.org>
> Tested-by: Nathan Chancellor <nathan@kernel.org>
>
> >
> >  drivers/gpu/drm/amd/display/Kconfig | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/=
display/Kconfig
> > index bf0a655d009e..901d1961b739 100644
> > --- a/drivers/gpu/drm/amd/display/Kconfig
> > +++ b/drivers/gpu/drm/amd/display/Kconfig
> > @@ -5,7 +5,7 @@ menu "Display Engine Configuration"
> >  config DRM_AMD_DC
> >       bool "AMD DC - Enable new display engine"
> >       default y
> > -     depends on BROKEN || !CC_IS_CLANG || X86_64 || SPARC64 || ARM64
> > +     depends on BROKEN || !CC_IS_CLANG || ARM64 || RISCV || SPARC64 ||=
 X86_64
> >       select SND_HDA_COMPONENT if SND_HDA_CORE
> >       # !CC_IS_CLANG: https://github.com/ClangBuiltLinux/linux/issues/1=
752
> >       select DRM_AMD_DC_FP if (X86 || LOONGARCH || (PPC64 && ALTIVEC) |=
| (ARM64 && KERNEL_MODE_NEON && !CC_IS_CLANG))
> > --
> > 2.40.1
> >