Hi Thomas, On Tue, Mar 12, 2024 at 4:48 PM Thomas Zimmermann <tzimmermann@xxxxxxx> wrote: > Add an fbdev emulation for SHMEM-based memory managers. The code is > similar to fbdev-generic, but does not require an addition shadow > buffer for mmap(). Fbdev-shmem operates directly on the buffer object's > SHMEM pages. Fbdev's deferred-I/O mechanism updates the hardware state > on write operations. > > Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx> Thanks for your patch! > --- /dev/null > +++ b/drivers/gpu/drm/drm_fbdev_shmem.c > +static int drm_fbdev_shmem_helper_fb_probe(struct drm_fb_helper *fb_helper, > + struct drm_fb_helper_surface_size *sizes) > +{ > + struct drm_client_dev *client = &fb_helper->client; > + struct drm_device *dev = fb_helper->dev; > + struct drm_client_buffer *buffer; > + struct drm_gem_shmem_object *shmem; > + struct drm_framebuffer *fb; > + struct fb_info *info; > + u32 format; > + struct iosys_map map; > + int ret; > + > + drm_dbg_kms(dev, "surface width(%d), height(%d) and bpp(%d)\n", > + sizes->surface_width, sizes->surface_height, > + sizes->surface_bpp); > + > + format = drm_mode_legacy_fb_format(sizes->surface_bpp, sizes->surface_depth); Oops, one more caller of the imprecise let's-guess-the-format-from-bpp-and-depth machinery to get rid of... > + buffer = drm_client_framebuffer_create(client, sizes->surface_width, > + sizes->surface_height, format); [...] > +} > +/** > + * drm_fbdev_shmem_setup() - Setup fbdev emulation for GEM SHMEM helpers > + * @dev: DRM device > + * @preferred_bpp: Preferred bits per pixel for the device. > + * 32 is used if this is zero. > + * > + * This function sets up fbdev emulation for GEM DMA drivers that support > + * dumb buffers with a virtual address and that can be mmap'ed. > + * drm_fbdev_shmem_setup() shall be called after the DRM driver registered > + * the new DRM device with drm_dev_register(). > + * > + * Restore, hotplug events and teardown are all taken care of. Drivers that do > + * suspend/resume need to call drm_fb_helper_set_suspend_unlocked() themselves. > + * Simple drivers might use drm_mode_config_helper_suspend(). > + * > + * This function is safe to call even when there are no connectors present. > + * Setup will be retried on the next hotplug event. > + * > + * The fbdev is destroyed by drm_dev_unregister(). > + */ > +void drm_fbdev_shmem_setup(struct drm_device *dev, unsigned int preferred_bpp) As this is a completely new function, can we please get a preferred_format parameter instead? > +{ > + struct drm_fb_helper *fb_helper; > + int ret; > + > + drm_WARN(dev, !dev->registered, "Device has not been registered.\n"); > + drm_WARN(dev, dev->fb_helper, "fb_helper is already set!\n"); > + > + fb_helper = kzalloc(sizeof(*fb_helper), GFP_KERNEL); > + if (!fb_helper) > + return; > + drm_fb_helper_prepare(dev, fb_helper, preferred_bpp, &drm_fbdev_shmem_helper_funcs); > + > + ret = drm_client_init(dev, &fb_helper->client, "fbdev", &drm_fbdev_shmem_client_funcs); > + if (ret) { > + drm_err(dev, "Failed to register client: %d\n", ret); > + goto err_drm_client_init; > + } > + > + drm_client_register(&fb_helper->client); > + > + return; > + > +err_drm_client_init: > + drm_fb_helper_unprepare(fb_helper); > + kfree(fb_helper); > +} > +EXPORT_SYMBOL(drm_fbdev_shmem_setup); Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx 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