6081905edf
The fblog drivers provides a replacement for fbcon and prints all kernel log messages to all available framebuffer devices. As long as the driver is not upstream, I will keep it here for reference. See linux-serial@vger.kernel.org for discussion. Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
118 lines
3.5 KiB
Diff
118 lines
3.5 KiB
Diff
From cab17dccb6026f9f33717db72f528f3b84d7393f Mon Sep 17 00:00:00 2001
|
|
From: David Herrmann <dh.herrmann@googlemail.com>
|
|
Date: Sat, 16 Jun 2012 23:07:50 +0200
|
|
Subject: [PATCH 06/10] fblog: allow enabling/disabling fblog on runtime
|
|
|
|
A sysfs file called "active" can be used to enable and disable fblog on
|
|
runtime. For example, the init-process can run "echo '0' >.../active"
|
|
after booting the system. This will allow other applications like X11 to
|
|
use the graphics subsystem. During shutdown, we can write '1' to get
|
|
system messages again.
|
|
|
|
When disabling fblog, we remove all framebuffers and will prevent new
|
|
hotplugged framebuffers from being added. When enabling fblog again, we
|
|
rescan the system for all framebuffers and resume operating.
|
|
|
|
The sysfs file is not registered, yet, as we do not have a "struct device"
|
|
yet. This will follow shortly, though.
|
|
|
|
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
|
|
---
|
|
Documentation/ABI/testing/sysfs-fblog | 9 ++++++
|
|
drivers/video/console/fblog.c | 49 +++++++++++++++++++++++++++++++++
|
|
2 files changed, 58 insertions(+)
|
|
create mode 100644 Documentation/ABI/testing/sysfs-fblog
|
|
|
|
diff --git a/Documentation/ABI/testing/sysfs-fblog b/Documentation/ABI/testing/sysfs-fblog
|
|
new file mode 100644
|
|
index 0000000..596393c
|
|
--- /dev/null
|
|
+++ b/Documentation/ABI/testing/sysfs-fblog
|
|
@@ -0,0 +1,9 @@
|
|
+What: /sys/class/graphics/fblog/active
|
|
+Date: June 2012
|
|
+KernelVersion: 3.6
|
|
+Contact: David Herrmann <dh.herrmann@googlemail.com>
|
|
+Description: Enable/Disable fblog. When setting this to 0, fblog will stop
|
|
+ writing to framebuffers and other applications can use the
|
|
+ graphics subsystem. When setting this to 1, fblog will rescan
|
|
+ the system for all framebuffers and resume drawing the kernel
|
|
+ log onto all framebuffers.
|
|
diff --git a/drivers/video/console/fblog.c b/drivers/video/console/fblog.c
|
|
index 7d4032e..9b05c56 100644
|
|
--- a/drivers/video/console/fblog.c
|
|
+++ b/drivers/video/console/fblog.c
|
|
@@ -92,6 +92,7 @@ struct fblog_fb {
|
|
};
|
|
|
|
static struct fblog_fb *fblog_fbs[FB_MAX];
|
|
+static atomic_t fblog_active;
|
|
|
|
static void fblog_buf_resize(struct fblog_buf *buf, size_t width,
|
|
size_t height)
|
|
@@ -338,6 +339,8 @@ static void fblog_register(struct fb_info *info)
|
|
const struct fb_videomode *mode;
|
|
unsigned int width, height;
|
|
|
|
+ if (!atomic_read(&fblog_active))
|
|
+ return;
|
|
if (!info || info->node < 0 || info->node >= FB_MAX)
|
|
return;
|
|
if (!registered_fb[info->node] || fblog_fbs[info->node])
|
|
@@ -428,6 +431,52 @@ static void fblog_refresh(struct fblog_fb *fb)
|
|
fblog_redraw(fb);
|
|
}
|
|
|
|
+static void fblog_activate(void)
|
|
+{
|
|
+ if (atomic_read(&fblog_active))
|
|
+ return;
|
|
+
|
|
+ atomic_set(&fblog_active, 1);
|
|
+ fblog_register_all();
|
|
+}
|
|
+
|
|
+static void fblog_deactivate(void)
|
|
+{
|
|
+ if (!atomic_read(&fblog_active))
|
|
+ return;
|
|
+
|
|
+ atomic_set(&fblog_active, 0);
|
|
+ fblog_unregister_all();
|
|
+}
|
|
+
|
|
+static ssize_t fblog_dev_active_show(struct device *dev,
|
|
+ struct device_attribute *attr,
|
|
+ char *buf)
|
|
+{
|
|
+ return snprintf(buf, PAGE_SIZE, "%d\n", atomic_read(&fblog_active));
|
|
+}
|
|
+
|
|
+static ssize_t fblog_dev_active_store(struct device *dev,
|
|
+ struct device_attribute *attr,
|
|
+ const char *buf,
|
|
+ size_t count)
|
|
+{
|
|
+ unsigned long num;
|
|
+
|
|
+ num = simple_strtoul(buf, NULL, 10);
|
|
+ console_lock();
|
|
+ if (num)
|
|
+ fblog_activate();
|
|
+ else
|
|
+ fblog_deactivate();
|
|
+ console_unlock();
|
|
+
|
|
+ return count;
|
|
+}
|
|
+
|
|
+static DEVICE_ATTR(active, S_IRUGO | S_IWUSR | S_IWGRP, fblog_dev_active_show,
|
|
+ fblog_dev_active_store);
|
|
+
|
|
static int __init fblog_init(void)
|
|
{
|
|
return 0;
|
|
--
|
|
1.7.10.4
|
|
|