From: Arnd Bergmann <arnd@kernel.org>
To: Lyude Paul <lyude@redhat.com>, Danilo Krummrich <dakr@kernel.org>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
David Airlie <airlied@gmail.com>, Simona Vetter <simona@ffwll.ch>,
Timur Tabi <ttabi@nvidia.com>
Cc: Arnd Bergmann <arnd@arndb.de>, Dave Airlie <airlied@redhat.com>,
Ben Skeggs <bskeggs@nvidia.com>,
dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] drm/nouveau: avoid -Wtautological-constant-out-of-range-compare warning
Date: Fri, 6 Mar 2026 16:06:44 +0100 [thread overview]
Message-ID: <20260306150650.465132-1-arnd@kernel.org> (raw)
From: Arnd Bergmann <arnd@arndb.de>
Checking a large 64-bit constant against a 32-bit dma_addr_t produces a harmless
compiler output when extra warnings are enabled, but leads to a build failure
with -Werror:
drivers/gpu/drm/nouveau/nvkm/subdev/fb/gb202.c:17:37: error: result of comparison of constant 4503599627370495 with expression of type 'dma_addr_t' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
17 | WARN_ON(fb->sysmem.flush_page_addr > DMA_BIT_MASK(52));
As the calculations of sysmem.flush_page_addr are mostly done on u64 types anyway,
change the struct member to the same type. This feels less invasive than changing
each WARN_ON() to add an extra cast or extended condition to shut up the warning.
Fixes: 31d3354f42c0 ("drm/nouveau: verify that hardware supports the flush page address")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/gpu/drm/nouveau/include/nvkm/subdev/fb.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/nouveau/include/nvkm/subdev/fb.h b/drivers/gpu/drm/nouveau/include/nvkm/subdev/fb.h
index e0d777a933e1..7b932449606b 100644
--- a/drivers/gpu/drm/nouveau/include/nvkm/subdev/fb.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/subdev/fb.h
@@ -38,7 +38,7 @@ struct nvkm_fb {
struct {
struct page *flush_page;
- dma_addr_t flush_page_addr;
+ u64 flush_page_addr;
} sysmem;
struct nvkm_ram *ram;
--
2.39.5
next reply other threads:[~2026-03-06 15:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-06 15:06 Arnd Bergmann [this message]
2026-03-08 22:46 ` Claude review: drm/nouveau: avoid -Wtautological-constant-out-of-range-compare warning Claude Code Review Bot
2026-03-08 22:46 ` Claude Code Review Bot
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260306150650.465132-1-arnd@kernel.org \
--to=arnd@kernel.org \
--cc=airlied@gmail.com \
--cc=airlied@redhat.com \
--cc=arnd@arndb.de \
--cc=bskeggs@nvidia.com \
--cc=dakr@kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lyude@redhat.com \
--cc=maarten.lankhorst@linux.intel.com \
--cc=mripard@kernel.org \
--cc=nouveau@lists.freedesktop.org \
--cc=simona@ffwll.ch \
--cc=ttabi@nvidia.com \
--cc=tzimmermann@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox