linux-zen-server/drivers/gpu/drm/i915/display/intel_fbdev.c

743 lines
20 KiB
C

/*
* Copyright © 2007 David Airlie
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Authors:
* David Airlie
*/
#include <linux/async.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/sysrq.h>
#include <linux/tty.h>
#include <linux/vga_switcheroo.h>
#include <drm/drm_crtc.h>
#include <drm/drm_fb_helper.h>
#include <drm/drm_fourcc.h>
#include "gem/i915_gem_lmem.h"
#include "i915_drv.h"
#include "intel_display_types.h"
#include "intel_fb.h"
#include "intel_fb_pin.h"
#include "intel_fbdev.h"
#include "intel_frontbuffer.h"
struct intel_fbdev {
struct drm_fb_helper helper;
struct intel_framebuffer *fb;
struct i915_vma *vma;
unsigned long vma_flags;
async_cookie_t cookie;
int preferred_bpp;
/* Whether or not fbdev hpd processing is temporarily suspended */
bool hpd_suspended: 1;
/* Set when a hotplug was received while HPD processing was suspended */
bool hpd_waiting: 1;
/* Protects hpd_suspended */
struct mutex hpd_lock;
};
static struct intel_frontbuffer *to_frontbuffer(struct intel_fbdev *ifbdev)
{
return ifbdev->fb->frontbuffer;
}
static void intel_fbdev_invalidate(struct intel_fbdev *ifbdev)
{
intel_frontbuffer_invalidate(to_frontbuffer(ifbdev), ORIGIN_CPU);
}
static int intel_fbdev_set_par(struct fb_info *info)
{
struct drm_fb_helper *fb_helper = info->par;
struct intel_fbdev *ifbdev =
container_of(fb_helper, struct intel_fbdev, helper);
int ret;
ret = drm_fb_helper_set_par(info);
if (ret == 0)
intel_fbdev_invalidate(ifbdev);
return ret;
}
static int intel_fbdev_blank(int blank, struct fb_info *info)
{
struct drm_fb_helper *fb_helper = info->par;
struct intel_fbdev *ifbdev =
container_of(fb_helper, struct intel_fbdev, helper);
int ret;
ret = drm_fb_helper_blank(blank, info);
if (ret == 0)
intel_fbdev_invalidate(ifbdev);
return ret;
}
static int intel_fbdev_pan_display(struct fb_var_screeninfo *var,
struct fb_info *info)
{
struct drm_fb_helper *fb_helper = info->par;
struct intel_fbdev *ifbdev =
container_of(fb_helper, struct intel_fbdev, helper);
int ret;
ret = drm_fb_helper_pan_display(var, info);
if (ret == 0)
intel_fbdev_invalidate(ifbdev);
return ret;
}
static const struct fb_ops intelfb_ops = {
.owner = THIS_MODULE,
DRM_FB_HELPER_DEFAULT_OPS,
.fb_set_par = intel_fbdev_set_par,
.fb_read = drm_fb_helper_cfb_read,
.fb_write = drm_fb_helper_cfb_write,
.fb_fillrect = drm_fb_helper_cfb_fillrect,
.fb_copyarea = drm_fb_helper_cfb_copyarea,
.fb_imageblit = drm_fb_helper_cfb_imageblit,
.fb_pan_display = intel_fbdev_pan_display,
.fb_blank = intel_fbdev_blank,
};
static int intelfb_alloc(struct drm_fb_helper *helper,
struct drm_fb_helper_surface_size *sizes)
{
struct intel_fbdev *ifbdev =
container_of(helper, struct intel_fbdev, helper);
struct drm_framebuffer *fb;
struct drm_device *dev = helper->dev;
struct drm_i915_private *dev_priv = to_i915(dev);
struct drm_mode_fb_cmd2 mode_cmd = {};
struct drm_i915_gem_object *obj;
int size;
/* we don't do packed 24bpp */
if (sizes->surface_bpp == 24)
sizes->surface_bpp = 32;
mode_cmd.width = sizes->surface_width;
mode_cmd.height = sizes->surface_height;
mode_cmd.pitches[0] = ALIGN(mode_cmd.width *
DIV_ROUND_UP(sizes->surface_bpp, 8), 64);
mode_cmd.pixel_format = drm_mode_legacy_fb_format(sizes->surface_bpp,
sizes->surface_depth);
size = mode_cmd.pitches[0] * mode_cmd.height;
size = PAGE_ALIGN(size);
obj = ERR_PTR(-ENODEV);
if (HAS_LMEM(dev_priv)) {
obj = i915_gem_object_create_lmem(dev_priv, size,
I915_BO_ALLOC_CONTIGUOUS);
} else {
/*
* If the FB is too big, just don't use it since fbdev is not very
* important and we should probably use that space with FBC or other
* features.
*/
if (size * 2 < dev_priv->dsm.usable_size)
obj = i915_gem_object_create_stolen(dev_priv, size);
if (IS_ERR(obj))
obj = i915_gem_object_create_shmem(dev_priv, size);
}
if (IS_ERR(obj)) {
drm_err(&dev_priv->drm, "failed to allocate framebuffer (%pe)\n", obj);
return PTR_ERR(obj);
}
fb = intel_framebuffer_create(obj, &mode_cmd);
i915_gem_object_put(obj);
if (IS_ERR(fb))
return PTR_ERR(fb);
ifbdev->fb = to_intel_framebuffer(fb);
return 0;
}
static int intelfb_create(struct drm_fb_helper *helper,
struct drm_fb_helper_surface_size *sizes)
{
struct intel_fbdev *ifbdev =
container_of(helper, struct intel_fbdev, helper);
struct intel_framebuffer *intel_fb = ifbdev->fb;
struct drm_device *dev = helper->dev;
struct drm_i915_private *dev_priv = to_i915(dev);
struct pci_dev *pdev = to_pci_dev(dev_priv->drm.dev);
struct i915_ggtt *ggtt = to_gt(dev_priv)->ggtt;
const struct i915_gtt_view view = {
.type = I915_GTT_VIEW_NORMAL,
};
intel_wakeref_t wakeref;
struct fb_info *info;
struct i915_vma *vma;
unsigned long flags = 0;
bool prealloc = false;
void __iomem *vaddr;
struct drm_i915_gem_object *obj;
struct i915_gem_ww_ctx ww;
int ret;
mutex_lock(&ifbdev->hpd_lock);
ret = ifbdev->hpd_suspended ? -EAGAIN : 0;
mutex_unlock(&ifbdev->hpd_lock);
if (ret)
return ret;
if (intel_fb &&
(sizes->fb_width > intel_fb->base.width ||
sizes->fb_height > intel_fb->base.height)) {
drm_dbg_kms(&dev_priv->drm,
"BIOS fb too small (%dx%d), we require (%dx%d),"
" releasing it\n",
intel_fb->base.width, intel_fb->base.height,
sizes->fb_width, sizes->fb_height);
drm_framebuffer_put(&intel_fb->base);
intel_fb = ifbdev->fb = NULL;
}
if (!intel_fb || drm_WARN_ON(dev, !intel_fb_obj(&intel_fb->base))) {
drm_dbg_kms(&dev_priv->drm,
"no BIOS fb, allocating a new one\n");
ret = intelfb_alloc(helper, sizes);
if (ret)
return ret;
intel_fb = ifbdev->fb;
} else {
drm_dbg_kms(&dev_priv->drm, "re-using BIOS fb\n");
prealloc = true;
sizes->fb_width = intel_fb->base.width;
sizes->fb_height = intel_fb->base.height;
}
wakeref = intel_runtime_pm_get(&dev_priv->runtime_pm);
/* Pin the GGTT vma for our access via info->screen_base.
* This also validates that any existing fb inherited from the
* BIOS is suitable for own access.
*/
vma = intel_pin_and_fence_fb_obj(&ifbdev->fb->base, false,
&view, false, &flags);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto out_unlock;
}
info = drm_fb_helper_alloc_info(helper);
if (IS_ERR(info)) {
drm_err(&dev_priv->drm, "Failed to allocate fb_info (%pe)\n", info);
ret = PTR_ERR(info);
goto out_unpin;
}
ifbdev->helper.fb = &ifbdev->fb->base;
info->fbops = &intelfb_ops;
obj = intel_fb_obj(&intel_fb->base);
if (i915_gem_object_is_lmem(obj)) {
struct intel_memory_region *mem = obj->mm.region;
/* Use fbdev's framebuffer from lmem for discrete */
info->fix.smem_start =
(unsigned long)(mem->io_start +
i915_gem_object_get_dma_address(obj, 0));
info->fix.smem_len = obj->base.size;
} else {
/* Our framebuffer is the entirety of fbdev's system memory */
info->fix.smem_start =
(unsigned long)(ggtt->gmadr.start + i915_ggtt_offset(vma));
info->fix.smem_len = vma->size;
}
for_i915_gem_ww(&ww, ret, false) {
ret = i915_gem_object_lock(vma->obj, &ww);
if (ret)
continue;
vaddr = i915_vma_pin_iomap(vma);
if (IS_ERR(vaddr)) {
drm_err(&dev_priv->drm,
"Failed to remap framebuffer into virtual memory (%pe)\n", vaddr);
ret = PTR_ERR(vaddr);
continue;
}
}
if (ret)
goto out_unpin;
info->screen_base = vaddr;
info->screen_size = vma->size;
drm_fb_helper_fill_info(info, &ifbdev->helper, sizes);
/* If the object is shmemfs backed, it will have given us zeroed pages.
* If the object is stolen however, it will be full of whatever
* garbage was left in there.
*/
if (!i915_gem_object_is_shmem(vma->obj) && !prealloc)
memset_io(info->screen_base, 0, info->screen_size);
/* Use default scratch pixmap (info->pixmap.flags = FB_PIXMAP_SYSTEM) */
drm_dbg_kms(&dev_priv->drm, "allocated %dx%d fb: 0x%08x\n",
ifbdev->fb->base.width, ifbdev->fb->base.height,
i915_ggtt_offset(vma));
ifbdev->vma = vma;
ifbdev->vma_flags = flags;
intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
vga_switcheroo_client_fb_set(pdev, info);
return 0;
out_unpin:
intel_unpin_fb_vma(vma, flags);
out_unlock:
intel_runtime_pm_put(&dev_priv->runtime_pm, wakeref);
return ret;
}
static int intelfb_dirty(struct drm_fb_helper *helper, struct drm_clip_rect *clip)
{
if (!(clip->x1 < clip->x2 && clip->y1 < clip->y2))
return 0;
if (helper->fb->funcs->dirty)
return helper->fb->funcs->dirty(helper->fb, NULL, 0, 0, clip, 1);
return 0;
}
static const struct drm_fb_helper_funcs intel_fb_helper_funcs = {
.fb_probe = intelfb_create,
.fb_dirty = intelfb_dirty,
};
static void intel_fbdev_destroy(struct intel_fbdev *ifbdev)
{
/* We rely on the object-free to release the VMA pinning for
* the info->screen_base mmaping. Leaking the VMA is simpler than
* trying to rectify all the possible error paths leading here.
*/
drm_fb_helper_fini(&ifbdev->helper);
if (ifbdev->vma)
intel_unpin_fb_vma(ifbdev->vma, ifbdev->vma_flags);
if (ifbdev->fb)
drm_framebuffer_remove(&ifbdev->fb->base);
drm_fb_helper_unprepare(&ifbdev->helper);
kfree(ifbdev);
}
/*
* Build an intel_fbdev struct using a BIOS allocated framebuffer, if possible.
* The core display code will have read out the current plane configuration,
* so we use that to figure out if there's an object for us to use as the
* fb, and if so, we re-use it for the fbdev configuration.
*
* Note we only support a single fb shared across pipes for boot (mostly for
* fbcon), so we just find the biggest and use that.
*/
static bool intel_fbdev_init_bios(struct drm_device *dev,
struct intel_fbdev *ifbdev)
{
struct drm_i915_private *i915 = to_i915(dev);
struct intel_framebuffer *fb = NULL;
struct intel_crtc *crtc;
unsigned int max_size = 0;
/* Find the largest fb */
for_each_intel_crtc(dev, crtc) {
struct intel_crtc_state *crtc_state =
to_intel_crtc_state(crtc->base.state);
struct intel_plane *plane =
to_intel_plane(crtc->base.primary);
struct intel_plane_state *plane_state =
to_intel_plane_state(plane->base.state);
struct drm_i915_gem_object *obj =
intel_fb_obj(plane_state->uapi.fb);
if (!crtc_state->uapi.active) {
drm_dbg_kms(&i915->drm,
"[CRTC:%d:%s] not active, skipping\n",
crtc->base.base.id, crtc->base.name);
continue;
}
if (!obj) {
drm_dbg_kms(&i915->drm,
"[PLANE:%d:%s] no fb, skipping\n",
plane->base.base.id, plane->base.name);
continue;
}
if (obj->base.size > max_size) {
drm_dbg_kms(&i915->drm,
"found possible fb from [PLANE:%d:%s]\n",
plane->base.base.id, plane->base.name);
fb = to_intel_framebuffer(plane_state->uapi.fb);
max_size = obj->base.size;
}
}
if (!fb) {
drm_dbg_kms(&i915->drm,
"no active fbs found, not using BIOS config\n");
goto out;
}
/* Now make sure all the pipes will fit into it */
for_each_intel_crtc(dev, crtc) {
struct intel_crtc_state *crtc_state =
to_intel_crtc_state(crtc->base.state);
struct intel_plane *plane =
to_intel_plane(crtc->base.primary);
unsigned int cur_size;
if (!crtc_state->uapi.active) {
drm_dbg_kms(&i915->drm,
"[CRTC:%d:%s] not active, skipping\n",
crtc->base.base.id, crtc->base.name);
continue;
}
drm_dbg_kms(&i915->drm, "checking [PLANE:%d:%s] for BIOS fb\n",
plane->base.base.id, plane->base.name);
/*
* See if the plane fb we found above will fit on this
* pipe. Note we need to use the selected fb's pitch and bpp
* rather than the current pipe's, since they differ.
*/
cur_size = crtc_state->uapi.adjusted_mode.crtc_hdisplay;
cur_size = cur_size * fb->base.format->cpp[0];
if (fb->base.pitches[0] < cur_size) {
drm_dbg_kms(&i915->drm,
"fb not wide enough for [PLANE:%d:%s] (%d vs %d)\n",
plane->base.base.id, plane->base.name,
cur_size, fb->base.pitches[0]);
fb = NULL;
break;
}
cur_size = crtc_state->uapi.adjusted_mode.crtc_vdisplay;
cur_size = intel_fb_align_height(&fb->base, 0, cur_size);
cur_size *= fb->base.pitches[0];
drm_dbg_kms(&i915->drm,
"[CRTC:%d:%s] area: %dx%d, bpp: %d, size: %d\n",
crtc->base.base.id, crtc->base.name,
crtc_state->uapi.adjusted_mode.crtc_hdisplay,
crtc_state->uapi.adjusted_mode.crtc_vdisplay,
fb->base.format->cpp[0] * 8,
cur_size);
if (cur_size > max_size) {
drm_dbg_kms(&i915->drm,
"fb not big enough for [PLANE:%d:%s] (%d vs %d)\n",
plane->base.base.id, plane->base.name,
cur_size, max_size);
fb = NULL;
break;
}
drm_dbg_kms(&i915->drm,
"fb big enough [PLANE:%d:%s] (%d >= %d)\n",
plane->base.base.id, plane->base.name,
max_size, cur_size);
}
if (!fb) {
drm_dbg_kms(&i915->drm,
"BIOS fb not suitable for all pipes, not using\n");
goto out;
}
ifbdev->preferred_bpp = fb->base.format->cpp[0] * 8;
ifbdev->fb = fb;
drm_framebuffer_get(&ifbdev->fb->base);
/* Final pass to check if any active pipes don't have fbs */
for_each_intel_crtc(dev, crtc) {
struct intel_crtc_state *crtc_state =
to_intel_crtc_state(crtc->base.state);
struct intel_plane *plane =
to_intel_plane(crtc->base.primary);
struct intel_plane_state *plane_state =
to_intel_plane_state(plane->base.state);
if (!crtc_state->uapi.active)
continue;
drm_WARN(dev, !plane_state->uapi.fb,
"re-used BIOS config but lost an fb on [PLANE:%d:%s]\n",
plane->base.base.id, plane->base.name);
}
drm_dbg_kms(&i915->drm, "using BIOS fb for initial console\n");
return true;
out:
return false;
}
static void intel_fbdev_suspend_worker(struct work_struct *work)
{
intel_fbdev_set_suspend(&container_of(work,
struct drm_i915_private,
display.fbdev.suspend_work)->drm,
FBINFO_STATE_RUNNING,
true);
}
int intel_fbdev_init(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = to_i915(dev);
struct intel_fbdev *ifbdev;
int ret;
if (drm_WARN_ON(dev, !HAS_DISPLAY(dev_priv)))
return -ENODEV;
ifbdev = kzalloc(sizeof(struct intel_fbdev), GFP_KERNEL);
if (ifbdev == NULL)
return -ENOMEM;
mutex_init(&ifbdev->hpd_lock);
drm_fb_helper_prepare(dev, &ifbdev->helper, 32, &intel_fb_helper_funcs);
if (intel_fbdev_init_bios(dev, ifbdev))
ifbdev->helper.preferred_bpp = ifbdev->preferred_bpp;
else
ifbdev->preferred_bpp = ifbdev->helper.preferred_bpp;
ret = drm_fb_helper_init(dev, &ifbdev->helper);
if (ret) {
kfree(ifbdev);
return ret;
}
dev_priv->display.fbdev.fbdev = ifbdev;
INIT_WORK(&dev_priv->display.fbdev.suspend_work, intel_fbdev_suspend_worker);
return 0;
}
static void intel_fbdev_initial_config(void *data, async_cookie_t cookie)
{
struct intel_fbdev *ifbdev = data;
/* Due to peculiar init order wrt to hpd handling this is separate. */
if (drm_fb_helper_initial_config(&ifbdev->helper))
intel_fbdev_unregister(to_i915(ifbdev->helper.dev));
}
void intel_fbdev_initial_config_async(struct drm_device *dev)
{
struct intel_fbdev *ifbdev = to_i915(dev)->display.fbdev.fbdev;
if (!ifbdev)
return;
ifbdev->cookie = async_schedule(intel_fbdev_initial_config, ifbdev);
}
static void intel_fbdev_sync(struct intel_fbdev *ifbdev)
{
if (!ifbdev->cookie)
return;
/* Only serialises with all preceding async calls, hence +1 */
async_synchronize_cookie(ifbdev->cookie + 1);
ifbdev->cookie = 0;
}
void intel_fbdev_unregister(struct drm_i915_private *dev_priv)
{
struct intel_fbdev *ifbdev = dev_priv->display.fbdev.fbdev;
if (!ifbdev)
return;
intel_fbdev_set_suspend(&dev_priv->drm, FBINFO_STATE_SUSPENDED, true);
if (!current_is_async())
intel_fbdev_sync(ifbdev);
drm_fb_helper_unregister_info(&ifbdev->helper);
}
void intel_fbdev_fini(struct drm_i915_private *dev_priv)
{
struct intel_fbdev *ifbdev = fetch_and_zero(&dev_priv->display.fbdev.fbdev);
if (!ifbdev)
return;
intel_fbdev_destroy(ifbdev);
}
/* Suspends/resumes fbdev processing of incoming HPD events. When resuming HPD
* processing, fbdev will perform a full connector reprobe if a hotplug event
* was received while HPD was suspended.
*/
static void intel_fbdev_hpd_set_suspend(struct drm_i915_private *i915, int state)
{
struct intel_fbdev *ifbdev = i915->display.fbdev.fbdev;
bool send_hpd = false;
mutex_lock(&ifbdev->hpd_lock);
ifbdev->hpd_suspended = state == FBINFO_STATE_SUSPENDED;
send_hpd = !ifbdev->hpd_suspended && ifbdev->hpd_waiting;
ifbdev->hpd_waiting = false;
mutex_unlock(&ifbdev->hpd_lock);
if (send_hpd) {
drm_dbg_kms(&i915->drm, "Handling delayed fbcon HPD event\n");
drm_fb_helper_hotplug_event(&ifbdev->helper);
}
}
void intel_fbdev_set_suspend(struct drm_device *dev, int state, bool synchronous)
{
struct drm_i915_private *dev_priv = to_i915(dev);
struct intel_fbdev *ifbdev = dev_priv->display.fbdev.fbdev;
struct fb_info *info;
if (!ifbdev)
return;
if (drm_WARN_ON(&dev_priv->drm, !HAS_DISPLAY(dev_priv)))
return;
if (!ifbdev->vma)
goto set_suspend;
info = ifbdev->helper.info;
if (synchronous) {
/* Flush any pending work to turn the console on, and then
* wait to turn it off. It must be synchronous as we are
* about to suspend or unload the driver.
*
* Note that from within the work-handler, we cannot flush
* ourselves, so only flush outstanding work upon suspend!
*/
if (state != FBINFO_STATE_RUNNING)
flush_work(&dev_priv->display.fbdev.suspend_work);
console_lock();
} else {
/*
* The console lock can be pretty contented on resume due
* to all the printk activity. Try to keep it out of the hot
* path of resume if possible.
*/
drm_WARN_ON(dev, state != FBINFO_STATE_RUNNING);
if (!console_trylock()) {
/* Don't block our own workqueue as this can
* be run in parallel with other i915.ko tasks.
*/
schedule_work(&dev_priv->display.fbdev.suspend_work);
return;
}
}
/* On resume from hibernation: If the object is shmemfs backed, it has
* been restored from swap. If the object is stolen however, it will be
* full of whatever garbage was left in there.
*/
if (state == FBINFO_STATE_RUNNING &&
!i915_gem_object_is_shmem(intel_fb_obj(&ifbdev->fb->base)))
memset_io(info->screen_base, 0, info->screen_size);
drm_fb_helper_set_suspend(&ifbdev->helper, state);
console_unlock();
set_suspend:
intel_fbdev_hpd_set_suspend(dev_priv, state);
}
void intel_fbdev_output_poll_changed(struct drm_device *dev)
{
struct intel_fbdev *ifbdev = to_i915(dev)->display.fbdev.fbdev;
bool send_hpd;
if (!ifbdev)
return;
intel_fbdev_sync(ifbdev);
mutex_lock(&ifbdev->hpd_lock);
send_hpd = !ifbdev->hpd_suspended;
ifbdev->hpd_waiting = true;
mutex_unlock(&ifbdev->hpd_lock);
if (send_hpd && (ifbdev->vma || ifbdev->helper.deferred_setup))
drm_fb_helper_hotplug_event(&ifbdev->helper);
}
void intel_fbdev_restore_mode(struct drm_device *dev)
{
struct intel_fbdev *ifbdev = to_i915(dev)->display.fbdev.fbdev;
if (!ifbdev)
return;
intel_fbdev_sync(ifbdev);
if (!ifbdev->vma)
return;
if (drm_fb_helper_restore_fbdev_mode_unlocked(&ifbdev->helper) == 0)
intel_fbdev_invalidate(ifbdev);
}
struct intel_framebuffer *intel_fbdev_framebuffer(struct intel_fbdev *fbdev)
{
if (!fbdev || !fbdev->helper.fb)
return NULL;
return to_intel_framebuffer(fbdev->helper.fb);
}