Hi Thomas,
On Mon, Apr 25, 2022 at 07:26:32PM +0200, Sam Ravnborg wrote:
Hi Thomas,
diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c index 6aaf6d0abf39..6924d489a289 100644 --- a/drivers/video/fbdev/core/fb_defio.c +++ b/drivers/video/fbdev/core/fb_defio.c @@ -181,6 +181,7 @@ int fb_deferred_io_mmap(struct fb_info *info, struct vm_area_struct *vma) vma->vm_private_data = info; return 0; } +EXPORT_SYMBOL_GPL(fb_deferred_io_mmap);
/* workqueue callback */ static void fb_deferred_io_work(struct work_struct *work) diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c index 84427470367b..52440e3f8f69 100644 --- a/drivers/video/fbdev/core/fbmem.c +++ b/drivers/video/fbdev/core/fbmem.c @@ -1334,7 +1334,6 @@ static int fb_mmap(struct file *file, struct vm_area_struct * vma) { struct fb_info *info = file_fb_info(file);
- int (*fb_mmap_fn)(struct fb_info *info, struct vm_area_struct *vma); unsigned long mmio_pgoff; unsigned long start; u32 len;
@@ -1343,14 +1342,7 @@ fb_mmap(struct file *file, struct vm_area_struct * vma) return -ENODEV; mutex_lock(&info->mm_lock);
- fb_mmap_fn = info->fbops->fb_mmap;
-#if IS_ENABLED(CONFIG_FB_DEFERRED_IO)
- if (info->fbdefio)
fb_mmap_fn = fb_deferred_io_mmap;-#endif
- if (fb_mmap_fn) {
if (info->fbops->fb_mmap) { int res;
/*
@@ -1358,11 +1350,18 @@ fb_mmap(struct file *file, struct vm_area_struct * vma) * SME protection is removed ahead of the call */ vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
res = fb_mmap_fn(info, vma);
res = info->fbops->fb_mmap(info, vma);mutex_unlock(&info->mm_lock); return res; }
/*
* FB deferred I/O wants you to handle mmap in your drivers. At a* minimum, point struct fb_ops.fb_mmap to fb_deferred_io_mmap().*/if (dev_WARN_ONCE(info->dev, info->fbdefio, "fbdev mmap not set up for defered I/O.\n"))
return -ENODEV;If not configured - then why not just call fb_deferred_io_mmap(), as this seems to be the default implementation anyway. Then drivers that needs it can override - and the rest fallback to the default.
Just to be clear - I already read: " Leave the mmap handling to drivers and expect them to call the helper for deferred I/O by thmeselves. "
But this does not help me understand why we need to explicit do what could be a simple default implementation. Chances are that I am stupid and it is obvious..
Sam