WARNING: unmet direct dependencies detected for DRM_GEM_SHMEM_HELPER Depends on [n]: HAS_IOMEM [=y] && DRM [=m] && MMU [=n] Selected by [m]: - DRM_SSD130X [=m] && HAS_IOMEM [=y] && DRM [=m]
DRM_GEM_SHMEM_HELPER depends on MMU, DRM_SSD130X should also depends on MMU.
Fixes: a61732e80867 ("drm: Add driver for Solomon SSD130x OLED displays") Signed-off-by: YueHaibing yuehaibing@huawei.com --- drivers/gpu/drm/solomon/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/solomon/Kconfig b/drivers/gpu/drm/solomon/Kconfig index 5861c3ab7c45..6230369505c9 100644 --- a/drivers/gpu/drm/solomon/Kconfig +++ b/drivers/gpu/drm/solomon/Kconfig @@ -1,6 +1,6 @@ config DRM_SSD130X tristate "DRM support for Solomon SSD130x OLED displays" - depends on DRM + depends on DRM && MMU select BACKLIGHT_CLASS_DEVICE select DRM_GEM_SHMEM_HELPER select DRM_KMS_HELPER
Hello YueHaibing,
Thanks for the patch.
On 3/12/22 07:34, YueHaibing wrote:
Indeed. All the DRM drivers that select DRM_GEM_SHMEM_HELPER depend on MMU.
Acked-by: Javier Martinez Canillas javierm@redhat.com
Hi Javier,
On Tue, Mar 15, 2022 at 12:28 PM Javier Martinez Canillas javierm@redhat.com wrote:
That's very unfortunate. Is there no way around this?
Else fbdev can never be deprecated in favor of DRM.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Mon, Apr 11, 2022 at 03:49:38PM +0200, Geert Uytterhoeven wrote:
I guess we could transparently replace shmem helpers by cma helpers on !MMU platforms - like if you have CONFIG_MMU you get the current shmem helpers, but if you don't have that, we do a dummy shmem helper implementation which uses cma helpers internally. The problem is that the interfaces have co-evolved and aren't a perfect match, so some surgery is probably required. Also we embed the structs into driver buffer object sturcts generally, and I'm not sure how to best solve that.
Maybe the simplest approach would be to add a pointer to cma_gem_object to shmem_gem_object for the !MMU case and do a bit of forwarding as necessary.
It might also be possible to wire through !MMU mmap support for shmem, but I'm not sure how well that will work in practice since that path would go to page_alloc and not through CMA (or maybe I'm just wrong about how mmap works on !MMU, definitely not my area of expertise).
Anyway should be fixable. -Daniel
dri-devel@lists.freedesktop.org
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Daniel Vetter -
Geert Uytterhoeven -
Javier Martinez Canillas -
YueHaibing