From: Arnd Bergmann <arnd@kernel.org>
To: Thomas Zimmermann <tzimmermann@suse.de>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
Maxime Ripard <maxime@cerno.tech>
Cc: Arnd Bergmann <arnd@arndb.de>, Rob Herring <robh+dt@kernel.org>,
Frank Rowand <frowand.list@gmail.com>,
Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org
Subject: [PATCH] fbdev: simplefb: fix Kconfig dependencies
Date: Wed, 21 Jul 2021 17:17:46 +0200 [thread overview]
Message-ID: <20210721151839.2484245-1-arnd@kernel.org> (raw)
From: Arnd Bergmann <arnd@arndb.de>
Configurations with both CONFIG_FB_SIMPLE=y and CONFIG_DRM_SIMPLEDRM=m
are allowed by Kconfig because the 'depends on !DRM_SIMPLEDRM' dependency
does not disallow FB_SIMPLE as long as SIMPLEDRM is not built-in. This
can however result in a build failure when cfb_fillrect() etc are then
also in loadable modules:
x86_64-linux-ld: drivers/video/fbdev/simplefb.o:(.rodata+0x1f8): undefined reference to `cfb_fillrect'
x86_64-linux-ld: drivers/video/fbdev/simplefb.o:(.rodata+0x200): undefined reference to `cfb_copyarea'
x86_64-linux-ld: drivers/video/fbdev/simplefb.o:(.rodata+0x208): undefined reference to `cfb_imageblit'
To work around this, change FB_SIMPLE to be a 'tristate' symbol,
which still allows both to be =m together, but not one of them to
be =y if the other one is =m. If a distro kernel picks this
configuration, it can be determined by local policy which of
the two modules gets loaded. The 'of_chosen' export is needed
as this is the first loadable module referencing it.
Alternatively, the Kconfig dependency could be changed to
'depends on DRM_SIMPLEDRM=n', which would forbid the configuration
with both drivers.
Fixes: 11e8f5fd223b ("drm: Add simpledrm driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
drivers/of/base.c | 1 +
drivers/video/fbdev/Kconfig | 5 +++--
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 48e941f99558..073ea7cd007b 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -36,6 +36,7 @@ LIST_HEAD(aliases_lookup);
struct device_node *of_root;
EXPORT_SYMBOL(of_root);
struct device_node *of_chosen;
+EXPORT_SYMBOL(of_chosen);
struct device_node *of_aliases;
struct device_node *of_stdout;
static const char *of_stdout_options;
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig
index 8a98539ec490..5fbcb3cc2e8e 100644
--- a/drivers/video/fbdev/Kconfig
+++ b/drivers/video/fbdev/Kconfig
@@ -2207,8 +2207,9 @@ config FB_HYPERV
This framebuffer driver supports Microsoft Hyper-V Synthetic Video.
config FB_SIMPLE
- bool "Simple framebuffer support"
- depends on (FB = y) && !DRM_SIMPLEDRM
+ tristate "Simple framebuffer support"
+ depends on FB
+ depends on !DRM_SIMPLEDRM
select FB_CFB_FILLRECT
select FB_CFB_COPYAREA
select FB_CFB_IMAGEBLIT
--
2.29.2
next reply other threads:[~2021-07-21 15:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-21 15:17 Arnd Bergmann [this message]
2021-07-21 16:29 ` [PATCH] fbdev: simplefb: fix Kconfig dependencies Rob Herring
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=20210721151839.2484245-1-arnd@kernel.org \
--to=arnd@kernel.org \
--cc=arnd@arndb.de \
--cc=daniel.vetter@ffwll.ch \
--cc=devicetree@vger.kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=frowand.list@gmail.com \
--cc=linux-fbdev@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lorenzo.pieralisi@arm.com \
--cc=maxime@cerno.tech \
--cc=mchehab+huawei@kernel.org \
--cc=robh+dt@kernel.org \
--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;
as well as URLs for NNTP newsgroup(s).