diff options
Diffstat (limited to 'drivers/gpu/drm/drm_fb_helper.c')
| -rw-r--r-- | drivers/gpu/drm/drm_fb_helper.c | 62 |
1 files changed, 14 insertions, 48 deletions
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index a7ba5b4902d6..8ebeccdeed23 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -46,6 +46,7 @@ #include <drm/drm_print.h> #include <drm/drm_vblank.h> +#include "drm_crtc_helper_internal.h" #include "drm_internal.h" static bool drm_fbdev_emulation = true; @@ -91,9 +92,12 @@ static DEFINE_MUTEX(kernel_fb_helper_lock); * * Drivers that support a dumb buffer with a virtual address and mmap support, * should try out the generic fbdev emulation using drm_fbdev_generic_setup(). + * It will automatically set up deferred I/O if the driver requires a shadow + * buffer. * - * Setup fbdev emulation by calling drm_fb_helper_fbdev_setup() and tear it - * down by calling drm_fb_helper_fbdev_teardown(). + * For other drivers, setup fbdev emulation by calling + * drm_fb_helper_fbdev_setup() and tear it down by calling + * drm_fb_helper_fbdev_teardown(). * * At runtime drivers should restore the fbdev console by using * drm_fb_helper_lastclose() as their &drm_driver.lastclose callback. @@ -126,8 +130,10 @@ static DEFINE_MUTEX(kernel_fb_helper_lock); * always run in process context since the fb_*() function could be running in * atomic context. If drm_fb_helper_deferred_io() is used as the deferred_io * callback it will also schedule dirty_work with the damage collected from the - * mmap page writes. Drivers can use drm_fb_helper_defio_init() to setup - * deferred I/O (coupled with drm_fb_helper_fbdev_teardown()). + * mmap page writes. + * + * Deferred I/O is not compatible with SHMEM. Such drivers should request an + * fbdev shadow buffer and call drm_fbdev_generic_setup() instead. */ static void drm_fb_helper_restore_lut_atomic(struct drm_crtc *crtc) @@ -679,49 +685,6 @@ void drm_fb_helper_deferred_io(struct fb_info *info, EXPORT_SYMBOL(drm_fb_helper_deferred_io); /** - * drm_fb_helper_defio_init - fbdev deferred I/O initialization - * @fb_helper: driver-allocated fbdev helper - * - * This function allocates &fb_deferred_io, sets callback to - * drm_fb_helper_deferred_io(), delay to 50ms and calls fb_deferred_io_init(). - * It should be called from the &drm_fb_helper_funcs->fb_probe callback. - * drm_fb_helper_fbdev_teardown() cleans up deferred I/O. - * - * NOTE: A copy of &fb_ops is made and assigned to &info->fbops. This is done - * because fb_deferred_io_cleanup() clears &fbops->fb_mmap and would thereby - * affect other instances of that &fb_ops. - * - * Returns: - * 0 on success or a negative error code on failure. - */ -int drm_fb_helper_defio_init(struct drm_fb_helper *fb_helper) -{ - struct fb_info *info = fb_helper->fbdev; - struct fb_deferred_io *fbdefio; - struct fb_ops *fbops; - - fbdefio = kzalloc(sizeof(*fbdefio), GFP_KERNEL); - fbops = kzalloc(sizeof(*fbops), GFP_KERNEL); - if (!fbdefio || !fbops) { - kfree(fbdefio); - kfree(fbops); - return -ENOMEM; - } - - info->fbdefio = fbdefio; - fbdefio->delay = msecs_to_jiffies(50); - fbdefio->deferred_io = drm_fb_helper_deferred_io; - - *fbops = *info->fbops; - info->fbops = fbops; - - fb_deferred_io_init(info); - - return 0; -} -EXPORT_SYMBOL(drm_fb_helper_defio_init); - -/** * drm_fb_helper_sys_read - wrapper around fb_sys_read * @info: fb_info struct pointer * @buf: userspace buffer to read from framebuffer memory @@ -2355,7 +2318,10 @@ static const struct drm_client_funcs drm_fbdev_client_funcs = { * * Drivers that set the dirty callback on their framebuffer will get a shadow * fbdev buffer that is blitted onto the real buffer. This is done in order to - * make deferred I/O work with all kinds of buffers. + * make deferred I/O work with all kinds of buffers. A shadow buffer can be + * requested explicitly by setting struct drm_mode_config.prefer_shadow or + * struct drm_mode_config.prefer_shadow_fbdev to true beforehand. This is + * required to use generic fbdev emulation with SHMEM helpers. * * This function is safe to call even when there are no connectors present. * Setup will be retried on the next hotplug event. |