On 03/10/2015 03:16 PM, Daniel Vetter wrote:
On Tue, Mar 10, 2015 at 03:11:28PM +0530, Archit Taneja wrote:
Legacy fbdev emulation support via DRM is achieved through KMS FB helpers. Most modesetting drivers enable provide fbdev emulation by default by selecting KMS FB helpers. A few provide a separate Kconfig option for the user to enable or disbale fbdev emulation.
Enabling fbdev emulation is finally a distro-level decision. Having a top level Kconfig option for fbdev emulation helps by providing a uniform way to enable/disable fbdev emulation for any modesetting driver. It also lets us remove unnecessary driver specific Kconfig options that causes bloat.
With a top level Kconfig in place, we can stub out the fb helper functions when not needed without breaking functionality. Having stub functions also prevents drivers to require wrapping fb helper function calls with #ifdefs.
DRM_FBDEV_EMULATION defaults to y since many drivers enable fbdev emulation by default and majority of distributions expect the fbdev interface in the kernel.
For now, this config selects both FB_SYS_* and FB_CFB_* configs as some modesetting drivers use the former and other the later. This needs to be taken care of in a better way.
Signed-off-by: Archit Taneja architt@codeaurora.org
drivers/gpu/drm/Kconfig | 18 +++++++ drivers/gpu/drm/Makefile | 4 ++ include/drm/drm_fb_helper.h | 120 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 142 insertions(+)
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index 151a050..38f83a0 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -40,6 +40,24 @@ config DRM_KMS_FB_HELPER help FBDEV helpers for KMS drivers.
+config DRM_FBDEV_EMULATION
- bool "Enable legacy fbdev support for your modesetting driver"
- depends on DRM
- select DRM_KMS_HELPER
- select DRM_KMS_FB_HELPER
- select FB_SYS_FILLRECT
- select FB_SYS_COPYAREA
- select FB_SYS_IMAGEBLIT
- select FB_SYS_FOPS
- select FB_CFB_FILLRECT
- select FB_CFB_COPYAREA
- select FB_CFB_IMAGEBLIT
- default y
- help
Choose this option if you have a need for the legacy fbdevsupport. Note that this support also provide the linux consolesupport on top of your modesetting driver.- config DRM_LOAD_EDID_FIRMWARE bool "Allow to specify an EDID data set instead of probing for it" depends on DRM_KMS_HELPER
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 2c239b9..c1d44b2 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -25,7 +25,11 @@ drm-$(CONFIG_OF) += drm_of.o drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \ drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
+ifeq ($(CONFIG_DRM_FBDEV_EMULATION),y) drm_kms_helper-$(CONFIG_DRM_KMS_FB_HELPER) += drm_fb_helper.o +endif
This should work as
drm_kms_helper-$CONFIG_DRM_FBDEV_EMULATION += drm_fb_helper.o
since both <modename>-y and <modename>-m are merged together.
Ah right. I'll fix that.
Archit