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authorNoralf Trønnes <noralf@tronnes.org>2016-04-28 17:18:34 +0200
committerDaniel Vetter <daniel.vetter@ffwll.ch>2016-05-02 16:24:49 +0200
commitba0263340a2aeaf5f08e4f2b0f4c29e300828b06 (patch)
tree47602035bd6b760a0d4fa93f1a9b1dc9401717f6 /include/linux/fb.h
parenteaa434defaca1781fb2932c685289b610aeb8b4b (diff)
fbdev: fb_defio: Export fb_deferred_io_mmap
Export fb_deferred_io_mmap so drivers can change vma->vm_page_prot. When the framebuffer memory is allocated using dma_alloc_writecombine() instead of vmalloc(), I get cache syncing problems on ARM. This solves it: static int drm_fbdev_cma_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma) { fb_deferred_io_mmap(info, vma); vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); return 0; } Could this have been done in the core? Drivers that don't set (struct fb_ops *)->fb_mmap, gets a call to fb_pgprotect() at the end of the default fb_mmap implementation (drivers/video/fbdev/core/fbmem.c). This is an architecture specific function that on many platforms uses pgprot_writecombine(), but not on all. And looking at some of the fb_mmap implementations, some of them sets vm_page_prot to nocache for instance, so I think the safest bet is to do this in the driver and not in the fbdev core. And we can't call fb_pgprotect() from fb_deferred_io_mmap() either because we don't have access to the file pointer that powerpc needs. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1461856717-6476-5-git-send-email-noralf@tronnes.org
Diffstat (limited to 'include/linux/fb.h')
-rw-r--r--include/linux/fb.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/fb.h b/include/linux/fb.h
index dfe88351341f..a964d076b4dc 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -673,6 +673,7 @@ static inline void __fb_pad_aligned_buffer(u8 *dst, u32 d_pitch,
}
/* drivers/video/fb_defio.c */
+int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma);
extern void fb_deferred_io_init(struct fb_info *info);
extern void fb_deferred_io_open(struct fb_info *info,
struct inode *inode,