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
