On 22/10/2024 15:55, Thomas Zimmermann wrote:
Hi
Am 22.10.24 um 15:31 schrieb Jon Hunter:
Hi Thomas,
On 12/03/2024 15:45, Thomas Zimmermann wrote:
Only TTM-based drivers use fbdev-generic. Rename it to fbdev-ttm and
change the symbol infix from _generic_ to _ttm_. Link the source file
into TTM helpers, so that it is only build if TTM-based drivers have
been selected. Select DRM_TTM_HELPER for loongson.
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
Documentation/gpu/drm-kms-helpers.rst | 2 +-
drivers/gpu/drm/Makefile | 5 +-
drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 6 +-
.../{drm_fbdev_generic.c => drm_fbdev_ttm.c} | 80 +++++++++----------
.../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 4 +-
drivers/gpu/drm/loongson/Kconfig | 1 +
drivers/gpu/drm/loongson/lsdc_drv.c | 4 +-
drivers/gpu/drm/nouveau/nouveau_drm.c | 6 +-
drivers/gpu/drm/qxl/qxl_drv.c | 4 +-
drivers/gpu/drm/tiny/bochs.c | 4 +-
drivers/gpu/drm/vboxvideo/vbox_drv.c | 4 +-
drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 4 +-
include/drm/drm_fbdev_generic.h | 15 ----
include/drm/drm_fbdev_ttm.h | 15 ++++
14 files changed, 77 insertions(+), 77 deletions(-)
rename drivers/gpu/drm/{drm_fbdev_generic.c => drm_fbdev_ttm.c} (76%)
delete mode 100644 include/drm/drm_fbdev_generic.h
create mode 100644 include/drm/drm_fbdev_ttm.h
...
diff --git a/include/drm/drm_fbdev_ttm.h b/include/drm/drm_fbdev_ttm.h
new file mode 100644
index 0000000000000..9e6c3bdf35376
--- /dev/null
+++ b/include/drm/drm_fbdev_ttm.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: MIT */
+
+#ifndef DRM_FBDEV_TTM_H
+#define DRM_FBDEV_TTM_H
+
+struct drm_device;
+
+#ifdef CONFIG_DRM_FBDEV_EMULATION
+void drm_fbdev_ttm_setup(struct drm_device *dev, unsigned int
preferred_bpp);
+#else
+static inline void drm_fbdev_ttm_setup(struct drm_device *dev,
unsigned int preferred_bpp)
+{ }
+#endif
+
+#endif
I recently noticed that with Linux v6.11 it is possible to enable
CONFIG_DRM_FBDEV_EMULATION without enabling CONFIG_DRM_TTM_HELPER. Now
while this does not currently cause any build issues, I believe that if
the function drm_fbdev_ttm_setup() is ever used somewhere that does not
explicitly select CONFIG_DRM_TTM_HELPER, then you could get a 'ERROR:
modpost: "drm_fbdev_ttm_setup"'.
So I was thinking that may be this should be ...
diff --git a/include/drm/drm_fbdev_ttm.h b/include/drm/drm_fbdev_ttm.h
index 9e6c3bdf3537..5b6723a37caa 100644
--- a/include/drm/drm_fbdev_ttm.h
+++ b/include/drm/drm_fbdev_ttm.h
@@ -5,7 +5,7 @@
struct drm_device;
-#ifdef CONFIG_DRM_FBDEV_EMULATION
+#if defined(CONFIG_DRM_FBDEV_EMULATION) &&
defined(CONFIG_DRM_TTM_HELPER)
void drm_fbdev_ttm_setup(struct drm_device *dev, unsigned int
preferred_bpp);
#else
static inline void drm_fbdev_ttm_setup(struct drm_device *dev,
unsigned int preferred_bpp)
The above function has been removed now in -next, but I believe we could
have the same problem with drm_fbdev_ttm_helper_fb_probe()?
We'd turn a linker/modpost error into a compiler error. Likely makes no
difference. And AFAICT every driver that selects TTM also selects
TTM_HELPER. Drivers without TTM should not use this header.
Yes I also noted that all the current drivers select TTM_HELPER and so
we don't run into this. However, it still seems a bit odd that we don't
expose a proper stub if TTM_HELPER is disabled (especially seeing as
there is a stub defined).
Jon
--
nvpublic
