* Thomas Zimmermann <tzimmermann@xxxxxxx> [240220 09:32]: > Am 20.02.24 um 09:56 schrieb Tony Lindgren: > > Oh right, yes omapdrm is operating on memory. > > With the latest kernels, you should see a warning if helpers operate on the > wrong type of memory. [1][2] OK > [1] https://elixir.bootlin.com/linux/v6.8-rc5/source/drivers/video/fbdev/core/fb_io_fops.c#L16 > [2] https://elixir.bootlin.com/linux/v6.8-rc5/source/drivers/video/fbdev/core/fb_sys_fops.c#L26 > > The following test patch works for me.. Not sure about the tracking though. > > I know that i915 doesn't track mmap'ed pages correctly and I've see systems > that do not update the framebuffer. IDK how/why this works with omapdrm. Sounds like the a similar issue might exist on omapdrm too then. > > Do you mean that tracking needs to be implemented if fb_deferred_io_mmap() > > did not work? > > omap_fbdev_fb_mmap() appears to mmap the DMA memory pages directly to > userspace. So the fb_dirty callback won't be invoked when userspace writes > to this framebuffer memory. > > To implement tracking, you'd need to set fb_mmap to fb_deferred_io_mmap(). > If you init omap_fb_ops with FB_DEFAULT_DEFERRED_OPS(), [3] you'd get that > automatically. fb_deferred_io_mmap() sets up the tracking whenever > userspaces writes to a mapped page. You also need to init the write-back > mechanisms that calls fb_dirty for the tracked pages. You should be able to > duplicate the code from [4] into omapdrm. OK great. Updated test patch below with FB_DEFAULT_DEFERRED_OPS, maybe that's all there is to it if I follow you :) The fb_dirty part was already done in patch 1/2. > [3] https://elixir.bootlin.com/linux/latest/source/include/linux/fb.h#L704 > [4] https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/drm_fbdev_generic.c#L119 Regards, Tony 8< --------------------------- diff --git a/drivers/gpu/drm/omapdrm/omap_fbdev.c b/drivers/gpu/drm/omapdrm/omap_fbdev.c --- a/drivers/gpu/drm/omapdrm/omap_fbdev.c +++ b/drivers/gpu/drm/omapdrm/omap_fbdev.c @@ -51,6 +51,10 @@ static void pan_worker(struct work_struct *work) omap_gem_roll(bo, fbi->var.yoffset * npages); } +FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(omap_fbdev, + drm_fb_helper_damage_range, + drm_fb_helper_damage_area) + static int omap_fbdev_pan_display(struct fb_var_screeninfo *var, struct fb_info *fbi) { @@ -76,15 +80,6 @@ static int omap_fbdev_pan_display(struct fb_var_screeninfo *var, return drm_fb_helper_pan_display(var, fbi); } -static int omap_fbdev_fb_mmap(struct fb_info *info, struct vm_area_struct *vma) -{ - struct drm_fb_helper *helper = info->par; - struct drm_framebuffer *fb = helper->fb; - struct drm_gem_object *bo = drm_gem_fb_get_obj(fb, 0); - - return drm_gem_mmap_obj(bo, omap_gem_mmap_size(bo), vma); -} - static void omap_fbdev_fb_destroy(struct fb_info *info) { struct drm_fb_helper *helper = info->par; @@ -94,6 +89,7 @@ static void omap_fbdev_fb_destroy(struct fb_info *info) DBG(); + fb_deferred_io_cleanup(info); drm_fb_helper_fini(helper); omap_gem_unpin(bo); @@ -106,15 +102,13 @@ static void omap_fbdev_fb_destroy(struct fb_info *info) static const struct fb_ops omap_fb_ops = { .owner = THIS_MODULE, - __FB_DEFAULT_DMAMEM_OPS_RDWR, + FB_DEFAULT_DEFERRED_OPS(omap_fbdev), .fb_check_var = drm_fb_helper_check_var, .fb_set_par = drm_fb_helper_set_par, .fb_setcmap = drm_fb_helper_setcmap, .fb_blank = drm_fb_helper_blank, .fb_pan_display = omap_fbdev_pan_display, - __FB_DEFAULT_DMAMEM_OPS_DRAW, .fb_ioctl = drm_fb_helper_ioctl, - .fb_mmap = omap_fbdev_fb_mmap, .fb_destroy = omap_fbdev_fb_destroy, }; @@ -213,6 +207,15 @@ static int omap_fbdev_create(struct drm_fb_helper *helper, fbi->fix.smem_start = dma_addr; fbi->fix.smem_len = bo->size; + /* deferred I/O */ + helper->fbdefio.delay = HZ / 20; + helper->fbdefio.deferred_io = drm_fb_helper_deferred_io; + + fbi->fbdefio = &helper->fbdefio; + ret = fb_deferred_io_init(fbi); + if (ret) + goto fail; + /* if we have DMM, then we can use it for scrolling by just * shuffling pages around in DMM rather than doing sw blit. */ diff --git a/include/linux/fb.h b/include/linux/fb.h --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -686,6 +686,10 @@ extern int fb_deferred_io_fsync(struct file *file, loff_t start, __FB_GEN_DEFAULT_DEFERRED_OPS_RDWR(__prefix, __damage_range, sys) \ __FB_GEN_DEFAULT_DEFERRED_OPS_DRAW(__prefix, __damage_area, sys) +#define FB_GEN_DEFAULT_DEFERRED_DMAMEM_OPS(__prefix, __damage_range, __damage_area) \ + __FB_GEN_DEFAULT_DEFERRED_OPS_RDWR(__prefix, __damage_range, sys) \ + __FB_GEN_DEFAULT_DEFERRED_OPS_DRAW(__prefix, __damage_area, sys) + /* * Initializes struct fb_ops for deferred I/O. */ -- 2.43.1
