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@xxxxxxxxx>> ---
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);
}
