On 03/10/2015 03:17 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 at 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 fbdev >> + support. Note that this support also provide the linux console >> + support on top of your modesetting driver. > > Maybe clarify that for linux console support you also need > CONFIG_FRAMEBUFFER_CONSOLE? fbdev alone isn't enough.
DRM_KMS_FB_HELPER selects that for us, right? Archit
