| Message ID | 20241025092538.38339-1-gonzalo.silvalde@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | fbdev: udl: Make CONFIG_FB_DEVICE optional | expand |
On 10/25/24 11:25, Gonzalo Silvalde Blanco wrote: > The fb_udl driver currently depends on CONFIG_FB_DEVICE to create sysfs > entries and access framebuffer device information. This patch wraps the > relevant code blocks with #ifdef CONFIG_FB_DEVICE, allowing the driver to > be built and used even if CONFIG_FB_DEVICE is not selected. > > The sysfs setting only controls access to certain framebuffer attributes > and is not required for the basic display functionality to work correctly. > (For information on DisplayLink devices and their Linux support, see: > https://wiki.archlinux.org/title/DisplayLink). > > Tested by building with and without CONFIG_FB_DEVICE, both of which > compiled and ran without issues. Gonzalo, I don't like this patch very much. It adds lots of #ifdefs around functions like dev_dbg(). Instead of ifdefs, aren't there other possibilities, e.g. using fb_dbg() if appropriate? Or using any other generic dbg() info or simply dropping the line? But more important: This is a fbdev driver and currently depends on CONFIG_FB_DEVICE. If I'm right, the only reason to disable CONFIG_FB_DEVICE is if you want fbdev output at bootup, but otherwise just want to use DRM. But then, doesn't there exist a native DRM driver for this graphics card which can be used instead? If so, I suggest to not change this fbdev driver at all. Helge > Signed-off-by: Gonzalo Silvalde Blanco <gonzalo.silvalde@gmail.com>> --- > drivers/video/fbdev/Kconfig | 1 - > drivers/video/fbdev/udlfb.c | 41 ++++++++++++++++++++++--------------- > 2 files changed, 24 insertions(+), 18 deletions(-) > > diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig > index ea36c6956bf3..9bf6cf74b9cb 100644 > --- a/drivers/video/fbdev/Kconfig > +++ b/drivers/video/fbdev/Kconfig > @@ -1588,7 +1588,6 @@ config FB_SMSCUFX > config FB_UDL > tristate "Displaylink USB Framebuffer support" > depends on FB && USB > - depends on FB_DEVICE > select FB_MODE_HELPERS > select FB_SYSMEM_HELPERS_DEFERRED > help > diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c > index 71ac9e36f67c..de4800f09dc7 100644 > --- a/drivers/video/fbdev/udlfb.c > +++ b/drivers/video/fbdev/udlfb.c > @@ -341,10 +341,10 @@ static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma) > return -EINVAL; > > pos = (unsigned long)info->fix.smem_start + offset; > - > +#ifdef CONFIG_FB_DEVICE > dev_dbg(info->dev, "mmap() framebuffer addr:%lu size:%lu\n", > pos, size); > - > +#endif > while (size > 0) { > page = vmalloc_to_pfn((void *)pos); > if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED)) > @@ -929,10 +929,10 @@ static int dlfb_ops_open(struct fb_info *info, int user) > info->fbdefio = fbdefio; > fb_deferred_io_init(info); > } > - > +#ifdef CONFIG_FB_DEVICE > dev_dbg(info->dev, "open, user=%d fb_info=%p count=%d\n", > user, info, dlfb->fb_count); > - > +#endif > return 0; > } > > @@ -982,9 +982,9 @@ static int dlfb_ops_release(struct fb_info *info, int user) > kfree(info->fbdefio); > info->fbdefio = NULL; > } > - > +#ifdef CONFIG_FB_DEVICE > dev_dbg(info->dev, "release, user=%d count=%d\n", user, dlfb->fb_count); > - > +#endif > return 0; > } > > @@ -1095,10 +1095,10 @@ static int dlfb_ops_blank(int blank_mode, struct fb_info *info) > struct dlfb_data *dlfb = info->par; > char *bufptr; > struct urb *urb; > - > +#ifdef CONFIG_FB_DEVICE > dev_dbg(info->dev, "blank, mode %d --> %d\n", > dlfb->blank_mode, blank_mode); > - > +#endif > if ((dlfb->blank_mode == FB_BLANK_POWERDOWN) && > (blank_mode != FB_BLANK_POWERDOWN)) { > > @@ -1190,7 +1190,9 @@ static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info > */ > new_fb = vmalloc(new_len); > if (!new_fb) { > +#ifdef CONFIG_FB_DEVICE > dev_err(info->dev, "Virtual framebuffer alloc failed\n"); > +#endif > return -ENOMEM; > } > memset(new_fb, 0xff, new_len); > @@ -1213,9 +1215,11 @@ static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info > */ > if (shadow) > new_back = vzalloc(new_len); > +#ifdef CONFIG_FB_DEVICE > if (!new_back) > dev_info(info->dev, > "No shadow/backing buffer allocated\n"); > +#endif > else { > dlfb_deferred_vfree(dlfb, dlfb->backing_buffer); > dlfb->backing_buffer = new_back; > @@ -1247,14 +1251,14 @@ static int dlfb_setup_modes(struct dlfb_data *dlfb, > struct device *dev = info->device; > struct fb_videomode *mode; > const struct fb_videomode *default_vmode = NULL; > - > +#ifdef CONFIG_FB_DEVICE > if (info->dev) { > /* only use mutex if info has been registered */ > mutex_lock(&info->lock); > /* parent device is used otherwise */ > dev = info->dev; > } > - > +#endif > edid = kmalloc(EDID_LENGTH, GFP_KERNEL); > if (!edid) { > result = -ENOMEM; > @@ -1375,10 +1379,10 @@ static int dlfb_setup_modes(struct dlfb_data *dlfb, > error: > if (edid && (dlfb->edid != edid)) > kfree(edid); > - > +#ifdef CONFIG_FB_DEVICE > if (info->dev) > mutex_unlock(&info->lock); > - > +#endif > return result; > } > > @@ -1597,8 +1601,10 @@ static int dlfb_parse_vendor_descriptor(struct dlfb_data *dlfb, > static int dlfb_usb_probe(struct usb_interface *intf, > const struct usb_device_id *id) > { > +#ifdef CONFIG_FB_DEVICE > int i; > const struct device_attribute *attr; > +#endif > struct dlfb_data *dlfb; > struct fb_info *info; > int retval; > @@ -1701,7 +1707,7 @@ static int dlfb_usb_probe(struct usb_interface *intf, > retval); > goto error; > } > - > +#ifdef CONFIG_FB_DEVICE > for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) { > attr = &fb_device_attrs[i]; > retval = device_create_file(info->dev, attr); > @@ -1710,17 +1716,16 @@ static int dlfb_usb_probe(struct usb_interface *intf, > "failed to create '%s' attribute: %d\n", > attr->attr.name, retval); > } > - > retval = device_create_bin_file(info->dev, &edid_attr); > if (retval) > dev_warn(info->device, "failed to create '%s' attribute: %d\n", > edid_attr.attr.name, retval); > - > dev_info(info->device, > "%s is DisplayLink USB device (%dx%d, %dK framebuffer memory)\n", > dev_name(info->dev), info->var.xres, info->var.yres, > ((dlfb->backing_buffer) ? > info->fix.smem_len * 2 : info->fix.smem_len) >> 10); > +#endif > return 0; > > error: > @@ -1737,8 +1742,9 @@ static void dlfb_usb_disconnect(struct usb_interface *intf) > { > struct dlfb_data *dlfb; > struct fb_info *info; > +#ifdef CONFIG_FB_DEVICE > int i; > - > +#endif > dlfb = usb_get_intfdata(intf); > info = dlfb->info; > > @@ -1754,10 +1760,11 @@ static void dlfb_usb_disconnect(struct usb_interface *intf) > dlfb_free_urb_list(dlfb); > > /* remove udlfb's sysfs interfaces */ > +#ifdef CONFIG_FB_DEVICE > for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) > device_remove_file(info->dev, &fb_device_attrs[i]); > device_remove_bin_file(info->dev, &edid_attr); > - > +#endif > unregister_framebuffer(info); > } >
Hi Helge, Thank you for your feedback. I understand the concern about the amount of #ifdefs. I’ll review the code to see if there are other ways to handle the conditional dependencies, perhaps by using fb_dbg() or similar, as you suggested. I agree that keeping readability is important, and I’ll explore options to simplify this. Regarding the reason for removing CONFIG_FB_DEVICE, my understanding is that this would allow the driver to be more flexible without that configuration in certain cases, as mentioned in the GPU TODO [1]. Thomas mentioned I could approach this driver with that in mind. However, if there’s a native DRM driver available that manages this device better, I could focus on other drivers instead. Would you then recommend that I work on drivers without native DRM support for this kind of task? I’d appreciate any specific suggestions on the approach here. Best regards, Gonzalo Silvalde Blanco [1] https://elixir.bootlin.com/linux/v6.11/source/Documentation/gpu/todo.rst#L459 On 25/10/24 17:37, Helge Deller <deller@gmx.de> wrote: > On 10/25/24 11:25, Gonzalo Silvalde Blanco wrote: > > The fb_udl driver currently depends on CONFIG_FB_DEVICE to create sysfs > > entries and access framebuffer device information. This patch wraps the > > relevant code blocks with #ifdef CONFIG_FB_DEVICE, allowing the driver to > > be built and used even if CONFIG_FB_DEVICE is not selected. > > > > The sysfs setting only controls access to certain framebuffer attributes > > and is not required for the basic display functionality to work > > correctly. > > (For information on DisplayLink devices and their Linux support, see: > > https://wiki.archlinux.org/title/DisplayLink). > > > > Tested by building with and without CONFIG_FB_DEVICE, both of which > > compiled and ran without issues. > > Gonzalo, I don't like this patch very much. > > It adds lots of #ifdefs around functions like dev_dbg(). > Instead of ifdefs, aren't there other possibilities, e.g. > using fb_dbg() if appropriate? > Or using any other generic dbg() info or simply dropping the line? > > But more important: > This is a fbdev driver and currently depends on CONFIG_FB_DEVICE. > If I'm right, the only reason to disable CONFIG_FB_DEVICE is if > you want fbdev output at bootup, but otherwise just want to use DRM. > But then, doesn't there exist a native DRM driver for this graphics > card which can be used instead? > If so, I suggest to not change this fbdev driver at all. > > Helge > > > Signed-off-by: Gonzalo Silvalde Blanco <gonzalo.silvalde@gmail.com>> --- > > drivers/video/fbdev/Kconfig | 1 - > > drivers/video/fbdev/udlfb.c | 41 ++++++++++++++++++++++--------------- > > 2 files changed, 24 insertions(+), 18 deletions(-) > > > > diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig > > index ea36c6956bf3..9bf6cf74b9cb 100644 > > --- a/drivers/video/fbdev/Kconfig > > +++ b/drivers/video/fbdev/Kconfig > > @@ -1588,7 +1588,6 @@ config FB_SMSCUFX > > config FB_UDL > > tristate "Displaylink USB Framebuffer support" > > depends on FB && USB > > - depends on FB_DEVICE > > select FB_MODE_HELPERS > > select FB_SYSMEM_HELPERS_DEFERRED > > help > > diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c > > index 71ac9e36f67c..de4800f09dc7 100644 > > --- a/drivers/video/fbdev/udlfb.c > > +++ b/drivers/video/fbdev/udlfb.c > > @@ -341,10 +341,10 @@ static int dlfb_ops_mmap(struct fb_info *info, > > struct vm_area_struct *vma) > > return -EINVAL; > > > > pos = (unsigned long)info->fix.smem_start + offset; > > - > > +#ifdef CONFIG_FB_DEVICE > > dev_dbg(info->dev, "mmap() framebuffer addr:%lu size:%lu\n", > > pos, size); > > - > > +#endif > > while (size > 0) { > > page = vmalloc_to_pfn((void *)pos); > > if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED)) > > @@ -929,10 +929,10 @@ static int dlfb_ops_open(struct fb_info *info, > > int user) > > info->fbdefio = fbdefio; > > fb_deferred_io_init(info); > > } > > - > > +#ifdef CONFIG_FB_DEVICE > > dev_dbg(info->dev, "open, user=%d fb_info=%p count=%d\n", > > user, info, dlfb->fb_count); > > - > > +#endif > > return 0; > > } > > > > @@ -982,9 +982,9 @@ static int dlfb_ops_release(struct fb_info *info, > > int user) > > kfree(info->fbdefio); > > info->fbdefio = NULL; > > } > > - > > +#ifdef CONFIG_FB_DEVICE > > dev_dbg(info->dev, "release, user=%d count=%d\n", user, > > dlfb->fb_count); > > - > > +#endif > > return 0; > > } > > > > @@ -1095,10 +1095,10 @@ static int dlfb_ops_blank(int blank_mode, > > struct fb_info *info) > > struct dlfb_data *dlfb = info->par; > > char *bufptr; > > struct urb *urb; > > - > > +#ifdef CONFIG_FB_DEVICE > > dev_dbg(info->dev, "blank, mode %d --> %d\n", > > dlfb->blank_mode, blank_mode); > > - > > +#endif > > if ((dlfb->blank_mode == FB_BLANK_POWERDOWN) && > > (blank_mode != FB_BLANK_POWERDOWN)) { > > > > @@ -1190,7 +1190,9 @@ static int dlfb_realloc_framebuffer(struct > > dlfb_data *dlfb, struct fb_info *info > > */ > > new_fb = vmalloc(new_len); > > if (!new_fb) { > > +#ifdef CONFIG_FB_DEVICE > > dev_err(info->dev, "Virtual framebuffer alloc failed\n"); > > +#endif > > return -ENOMEM; > > } > > memset(new_fb, 0xff, new_len); > > @@ -1213,9 +1215,11 @@ static int dlfb_realloc_framebuffer(struct > > dlfb_data *dlfb, struct fb_info *info > > */ > > if (shadow) > > new_back = vzalloc(new_len); > > +#ifdef CONFIG_FB_DEVICE > > if (!new_back) > > dev_info(info->dev, > > "No shadow/backing buffer allocated\n"); > > +#endif > > else { > > dlfb_deferred_vfree(dlfb, dlfb->backing_buffer); > > dlfb->backing_buffer = new_back; > > @@ -1247,14 +1251,14 @@ static int dlfb_setup_modes(struct dlfb_data > > *dlfb, > > struct device *dev = info->device; > > struct fb_videomode *mode; > > const struct fb_videomode *default_vmode = NULL; > > - > > +#ifdef CONFIG_FB_DEVICE > > if (info->dev) { > > /* only use mutex if info has been registered */ > > mutex_lock(&info->lock); > > /* parent device is used otherwise */ > > dev = info->dev; > > } > > - > > +#endif > > edid = kmalloc(EDID_LENGTH, GFP_KERNEL); > > if (!edid) { > > result = -ENOMEM; > > @@ -1375,10 +1379,10 @@ static int dlfb_setup_modes(struct dlfb_data > > *dlfb, > > error: > > if (edid && (dlfb->edid != edid)) > > kfree(edid); > > - > > +#ifdef CONFIG_FB_DEVICE > > if (info->dev) > > mutex_unlock(&info->lock); > > - > > +#endif > > return result; > > } > > > > @@ -1597,8 +1601,10 @@ static int dlfb_parse_vendor_descriptor(struct > > dlfb_data *dlfb, > > static int dlfb_usb_probe(struct usb_interface *intf, > > const struct usb_device_id *id) > > { > > +#ifdef CONFIG_FB_DEVICE > > int i; > > const struct device_attribute *attr; > > +#endif > > struct dlfb_data *dlfb; > > struct fb_info *info; > > int retval; > > @@ -1701,7 +1707,7 @@ static int dlfb_usb_probe(struct usb_interface > > *intf, > > retval); > > goto error; > > } > > - > > +#ifdef CONFIG_FB_DEVICE > > for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) { > > attr = &fb_device_attrs[i]; > > retval = device_create_file(info->dev, attr); > > @@ -1710,17 +1716,16 @@ static int dlfb_usb_probe(struct usb_interface > > *intf, > > "failed to create '%s' attribute: %d\n", > > attr->attr.name, retval); > > } > > - > > retval = device_create_bin_file(info->dev, &edid_attr); > > if (retval) > > dev_warn(info->device, "failed to create '%s' attribute: %d\n", > > edid_attr.attr.name, retval); > > - > > dev_info(info->device, > > "%s is DisplayLink USB device (%dx%d, %dK framebuffer > > memory)\n", > > dev_name(info->dev), info->var.xres, info->var.yres, > > ((dlfb->backing_buffer) ? > > info->fix.smem_len * 2 : info->fix.smem_len) >> 10); > > +#endif > > return 0; > > > > error: > > @@ -1737,8 +1742,9 @@ static void dlfb_usb_disconnect(struct > > usb_interface *intf) > > { > > struct dlfb_data *dlfb; > > struct fb_info *info; > > +#ifdef CONFIG_FB_DEVICE > > int i; > > - > > +#endif > > dlfb = usb_get_intfdata(intf); > > info = dlfb->info; > > > > @@ -1754,10 +1760,11 @@ static void dlfb_usb_disconnect(struct > > usb_interface *intf) > > dlfb_free_urb_list(dlfb); > > > > /* remove udlfb's sysfs interfaces */ > > +#ifdef CONFIG_FB_DEVICE > > for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) > > device_remove_file(info->dev, &fb_device_attrs[i]); > > device_remove_bin_file(info->dev, &edid_attr); > > - > > +#endif > > unregister_framebuffer(info); > > } > > > >
Hi Gonzalo, kernel test robot noticed the following build warnings: [auto build test WARNING on drm-misc/drm-misc-next] [also build test WARNING on drm-tip/drm-tip linus/master v6.12-rc4 next-20241025] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Gonzalo-Silvalde-Blanco/fbdev-udl-Make-CONFIG_FB_DEVICE-optional/20241025-172653 base: git://anongit.freedesktop.org/drm/drm-misc drm-misc-next patch link: https://lore.kernel.org/r/20241025092538.38339-1-gonzalo.silvalde%40gmail.com patch subject: [PATCH] fbdev: udl: Make CONFIG_FB_DEVICE optional config: i386-randconfig-r121-20241027 (https://download.01.org/0day-ci/archive/20241028/202410280002.AXteAJwc-lkp@intel.com/config) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241028/202410280002.AXteAJwc-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202410280002.AXteAJwc-lkp@intel.com/ All warnings (new ones prefixed by >>): >> drivers/video/fbdev/udlfb.c:1493:38: warning: 'fb_device_attrs' defined but not used [-Wunused-const-variable=] 1493 | static const struct device_attribute fb_device_attrs[] = { | ^~~~~~~~~~~~~~~ >> drivers/video/fbdev/udlfb.c:1485:35: warning: 'edid_attr' defined but not used [-Wunused-const-variable=] 1485 | static const struct bin_attribute edid_attr = { | ^~~~~~~~~ vim +/fb_device_attrs +1493 drivers/video/fbdev/udlfb.c 7d9485e2c53caa drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-02-15 1484 598b2eedfc3fbe drivers/video/fbdev/udlfb.c Bhumika Goyal 2017-08-18 @1485 static const struct bin_attribute edid_attr = { 7d9485e2c53caa drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-02-15 1486 .attr.name = "edid", 8ef8cc4fca4a92 drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-09-05 1487 .attr.mode = 0666, b9f03a3cd06c6f drivers/video/udlfb.c Paul Mundt 2011-01-06 1488 .size = EDID_LENGTH, 7d9485e2c53caa drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-02-15 1489 .read = edid_show, 8ef8cc4fca4a92 drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-09-05 1490 .write = edid_store 7d9485e2c53caa drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-02-15 1491 }; 7d9485e2c53caa drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-02-15 1492 fa738a5c4b2a6b drivers/video/fbdev/udlfb.c Ladislav Michl 2018-01-16 @1493 static const struct device_attribute fb_device_attrs[] = { 7d9485e2c53caa drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-02-15 1494 __ATTR_RO(metrics_bytes_rendered), 7d9485e2c53caa drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-02-15 1495 __ATTR_RO(metrics_bytes_identical), 7d9485e2c53caa drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-02-15 1496 __ATTR_RO(metrics_bytes_sent), 7d9485e2c53caa drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-02-15 1497 __ATTR_RO(metrics_cpu_kcycles_used), 926c11151e3b82 drivers/staging/udlfb/udlfb.c Greg Kroah-Hartman 2010-11-18 1498 __ATTR(metrics_reset, S_IWUSR, NULL, metrics_reset_store), 7d9485e2c53caa drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-02-15 1499 }; 7d9485e2c53caa drivers/staging/udlfb/udlfb.c Bernie Thompson 2010-02-15 1500
diff --git a/drivers/video/fbdev/Kconfig b/drivers/video/fbdev/Kconfig index ea36c6956bf3..9bf6cf74b9cb 100644 --- a/drivers/video/fbdev/Kconfig +++ b/drivers/video/fbdev/Kconfig @@ -1588,7 +1588,6 @@ config FB_SMSCUFX config FB_UDL tristate "Displaylink USB Framebuffer support" depends on FB && USB - depends on FB_DEVICE select FB_MODE_HELPERS select FB_SYSMEM_HELPERS_DEFERRED help diff --git a/drivers/video/fbdev/udlfb.c b/drivers/video/fbdev/udlfb.c index 71ac9e36f67c..de4800f09dc7 100644 --- a/drivers/video/fbdev/udlfb.c +++ b/drivers/video/fbdev/udlfb.c @@ -341,10 +341,10 @@ static int dlfb_ops_mmap(struct fb_info *info, struct vm_area_struct *vma) return -EINVAL; pos = (unsigned long)info->fix.smem_start + offset; - +#ifdef CONFIG_FB_DEVICE dev_dbg(info->dev, "mmap() framebuffer addr:%lu size:%lu\n", pos, size); - +#endif while (size > 0) { page = vmalloc_to_pfn((void *)pos); if (remap_pfn_range(vma, start, page, PAGE_SIZE, PAGE_SHARED)) @@ -929,10 +929,10 @@ static int dlfb_ops_open(struct fb_info *info, int user) info->fbdefio = fbdefio; fb_deferred_io_init(info); } - +#ifdef CONFIG_FB_DEVICE dev_dbg(info->dev, "open, user=%d fb_info=%p count=%d\n", user, info, dlfb->fb_count); - +#endif return 0; } @@ -982,9 +982,9 @@ static int dlfb_ops_release(struct fb_info *info, int user) kfree(info->fbdefio); info->fbdefio = NULL; } - +#ifdef CONFIG_FB_DEVICE dev_dbg(info->dev, "release, user=%d count=%d\n", user, dlfb->fb_count); - +#endif return 0; } @@ -1095,10 +1095,10 @@ static int dlfb_ops_blank(int blank_mode, struct fb_info *info) struct dlfb_data *dlfb = info->par; char *bufptr; struct urb *urb; - +#ifdef CONFIG_FB_DEVICE dev_dbg(info->dev, "blank, mode %d --> %d\n", dlfb->blank_mode, blank_mode); - +#endif if ((dlfb->blank_mode == FB_BLANK_POWERDOWN) && (blank_mode != FB_BLANK_POWERDOWN)) { @@ -1190,7 +1190,9 @@ static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info */ new_fb = vmalloc(new_len); if (!new_fb) { +#ifdef CONFIG_FB_DEVICE dev_err(info->dev, "Virtual framebuffer alloc failed\n"); +#endif return -ENOMEM; } memset(new_fb, 0xff, new_len); @@ -1213,9 +1215,11 @@ static int dlfb_realloc_framebuffer(struct dlfb_data *dlfb, struct fb_info *info */ if (shadow) new_back = vzalloc(new_len); +#ifdef CONFIG_FB_DEVICE if (!new_back) dev_info(info->dev, "No shadow/backing buffer allocated\n"); +#endif else { dlfb_deferred_vfree(dlfb, dlfb->backing_buffer); dlfb->backing_buffer = new_back; @@ -1247,14 +1251,14 @@ static int dlfb_setup_modes(struct dlfb_data *dlfb, struct device *dev = info->device; struct fb_videomode *mode; const struct fb_videomode *default_vmode = NULL; - +#ifdef CONFIG_FB_DEVICE if (info->dev) { /* only use mutex if info has been registered */ mutex_lock(&info->lock); /* parent device is used otherwise */ dev = info->dev; } - +#endif edid = kmalloc(EDID_LENGTH, GFP_KERNEL); if (!edid) { result = -ENOMEM; @@ -1375,10 +1379,10 @@ static int dlfb_setup_modes(struct dlfb_data *dlfb, error: if (edid && (dlfb->edid != edid)) kfree(edid); - +#ifdef CONFIG_FB_DEVICE if (info->dev) mutex_unlock(&info->lock); - +#endif return result; } @@ -1597,8 +1601,10 @@ static int dlfb_parse_vendor_descriptor(struct dlfb_data *dlfb, static int dlfb_usb_probe(struct usb_interface *intf, const struct usb_device_id *id) { +#ifdef CONFIG_FB_DEVICE int i; const struct device_attribute *attr; +#endif struct dlfb_data *dlfb; struct fb_info *info; int retval; @@ -1701,7 +1707,7 @@ static int dlfb_usb_probe(struct usb_interface *intf, retval); goto error; } - +#ifdef CONFIG_FB_DEVICE for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) { attr = &fb_device_attrs[i]; retval = device_create_file(info->dev, attr); @@ -1710,17 +1716,16 @@ static int dlfb_usb_probe(struct usb_interface *intf, "failed to create '%s' attribute: %d\n", attr->attr.name, retval); } - retval = device_create_bin_file(info->dev, &edid_attr); if (retval) dev_warn(info->device, "failed to create '%s' attribute: %d\n", edid_attr.attr.name, retval); - dev_info(info->device, "%s is DisplayLink USB device (%dx%d, %dK framebuffer memory)\n", dev_name(info->dev), info->var.xres, info->var.yres, ((dlfb->backing_buffer) ? info->fix.smem_len * 2 : info->fix.smem_len) >> 10); +#endif return 0; error: @@ -1737,8 +1742,9 @@ static void dlfb_usb_disconnect(struct usb_interface *intf) { struct dlfb_data *dlfb; struct fb_info *info; +#ifdef CONFIG_FB_DEVICE int i; - +#endif dlfb = usb_get_intfdata(intf); info = dlfb->info; @@ -1754,10 +1760,11 @@ static void dlfb_usb_disconnect(struct usb_interface *intf) dlfb_free_urb_list(dlfb); /* remove udlfb's sysfs interfaces */ +#ifdef CONFIG_FB_DEVICE for (i = 0; i < ARRAY_SIZE(fb_device_attrs); i++) device_remove_file(info->dev, &fb_device_attrs[i]); device_remove_bin_file(info->dev, &edid_attr); - +#endif unregister_framebuffer(info); }
The fb_udl driver currently depends on CONFIG_FB_DEVICE to create sysfs entries and access framebuffer device information. This patch wraps the relevant code blocks with #ifdef CONFIG_FB_DEVICE, allowing the driver to be built and used even if CONFIG_FB_DEVICE is not selected. The sysfs setting only controls access to certain framebuffer attributes and is not required for the basic display functionality to work correctly. (For information on DisplayLink devices and their Linux support, see: https://wiki.archlinux.org/title/DisplayLink). Tested by building with and without CONFIG_FB_DEVICE, both of which compiled and ran without issues. Signed-off-by: Gonzalo Silvalde Blanco <gonzalo.silvalde@gmail.com> --- drivers/video/fbdev/Kconfig | 1 - drivers/video/fbdev/udlfb.c | 41 ++++++++++++++++++++++--------------- 2 files changed, 24 insertions(+), 18 deletions(-)