[RFC PATCH 0/2] fbcon: user-defined cursor blink interval

[RFC PATCH 0/2] fbcon: user-defined cursor blink interval

[Scot Doyle]

Allow users to set fbcon's cursor blink interval. The current interval
of 200 milliseconds is retained as the default.

Tested with intelfb.

Scot Doyle (2):
  fbcon: store cursor blink interval in fbcon_ops
  fbcon: expose cursor blink interval via sysfs

 drivers/video/console/fbcon.c | 80 +++++++++++++++++++++++++++++++++++++++++--
 drivers/video/console/fbcon.h |  1 +
 2 files changed, 79 insertions(+), 2 deletions(-)

-- 
2.1.4

[RFC PATCH 1/2] fbcon: store cursor blink interval in fbcon_ops

[Scot Doyle]

The fbcon cursor, when set to blink, is hardcoded to toggle display state
five times per second. Move this setting to a the driver's fbdev_ops
structure, retaining the default blink interval.

Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
---
 drivers/video/console/fbcon.c | 5 +++--
 drivers/video/console/fbcon.h | 1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index ea43724..7a2030b 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -405,7 +405,7 @@ static void cursor_timer_handler(unsigned long dev_addr)
 	struct fbcon_ops *ops = info->fbcon_par;
 
 	queue_work(system_power_efficient_wq, &info->queue);
-	mod_timer(&ops->cursor_timer, jiffies + HZ/5);
+	mod_timer(&ops->cursor_timer, jiffies + ops->blink_jiffies);
 }
 
 static void fbcon_add_cursor_timer(struct fb_info *info)
@@ -420,7 +420,7 @@ static void fbcon_add_cursor_timer(struct fb_info *info)
 
 		init_timer(&ops->cursor_timer);
 		ops->cursor_timer.function = cursor_timer_handler;
-		ops->cursor_timer.expires = jiffies + HZ / 5;
+		ops->cursor_timer.expires = jiffies + ops->blink_jiffies;
 		ops->cursor_timer.data = (unsigned long ) info;
 		add_timer(&ops->cursor_timer);
 		ops->flags |= FBCON_FLAGS_CURSOR_TIMER;
@@ -959,6 +959,7 @@ static const char *fbcon_startup(void)
 	ops->currcon = -1;
 	ops->graphics = 1;
 	ops->cur_rotate = -1;
+	ops->blink_jiffies = msecs_to_jiffies(200);
 	info->fbcon_par = ops;
 	p->con_rotate = initial_rotation;
 	set_blitting_type(vc, info);
diff --git a/drivers/video/console/fbcon.h b/drivers/video/console/fbcon.h
index 6bd2e0c..642c4e7 100644
--- a/drivers/video/console/fbcon.h
+++ b/drivers/video/console/fbcon.h
@@ -70,6 +70,7 @@ struct fbcon_ops {
 	struct fb_cursor cursor_state;
 	struct display *p;
         int    currcon;	                /* Current VC. */
+	int    blink_jiffies;
 	int    cursor_flash;
 	int    cursor_reset;
 	int    blank_state;
-- 
2.1.4

[RFC PATCH 2/2] fbcon: expose cursor blink interval via sysfs

[Scot Doyle]

The fbcon cursor, when set to blink, is hardcoded to toggle display state
five times per second. Expose this setting via
/sys/class/graphics/fbcon/cursor_blink_ms

Values written to the interface set the approximate time interval in
milliseconds between cursor toggles, from 1 to 32767. Since the interval
is stored internally as a number of jiffies, the millisecond value read
from the interface may not exactly match the entered value.

An outstanding blink timer is reset after a new value is entered.

If the cursor blink is disabled, either via the 'cursor_blink' boolean
setting or some other mechanism, the 'cursor_blink_ms' setting may still
be modified. The new value will be used if the blink is reactivated.

Tested with intelfb.

Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
---
 drivers/video/console/fbcon.c | 75 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)

diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 7a2030b..0ddfcf6 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -3495,11 +3495,86 @@ err:
 	return count;
 }
 
+static ssize_t show_cursor_blink_ms(struct device *device,
+				    struct device_attribute *attr, char *buf)
+{
+	struct fb_info *info;
+	struct fbcon_ops *ops;
+	int idx, ms = -1;
+
+	if (fbcon_has_exited)
+		return 0;
+
+	console_lock();
+	idx = con2fb_map[fg_console];
+
+	if (idx == -1 || registered_fb[idx] == NULL)
+		goto err;
+
+	info = registered_fb[idx];
+	ops = info->fbcon_par;
+
+	if (!ops)
+		goto err;
+
+	ms = jiffies_to_msecs(ops->blink_jiffies);
+
+err:
+	console_unlock();
+	return snprintf(buf, PAGE_SIZE, "%d\n", ms);
+}
+
+static ssize_t store_cursor_blink_ms(struct device *device,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct fb_info *info;
+	struct fbcon_ops *ops;
+	int idx;
+	unsigned long ms;
+
+	if (fbcon_has_exited)
+		return count;
+
+	console_lock();
+	idx = con2fb_map[fg_console];
+
+	if (idx == -1 || registered_fb[idx] == NULL)
+		goto err;
+
+	info = registered_fb[idx];
+
+	if (!info->fbcon_par)
+		goto err;
+
+	ops = info->fbcon_par;
+
+	if (!ops)
+		goto err;
+
+	if (!kstrtoul(buf, 0, &ms)) {
+		ms = min_t(unsigned long, ms, SHRT_MAX);
+		ops->blink_jiffies = max_t(int, msecs_to_jiffies(ms), 1);
+
+		if (info->queue.func == fb_flashcursor &&
+		    ops->flags & FBCON_FLAGS_CURSOR_TIMER) {
+			fbcon_del_cursor_timer(info);
+			fbcon_add_cursor_timer(info);
+		}
+	}
+
+err:
+	console_unlock();
+	return count;
+}
+
 static struct device_attribute device_attrs[] = {
 	__ATTR(rotate, S_IRUGO|S_IWUSR, show_rotate, store_rotate),
 	__ATTR(rotate_all, S_IWUSR, NULL, store_rotate_all),
 	__ATTR(cursor_blink, S_IRUGO|S_IWUSR, show_cursor_blink,
 	       store_cursor_blink),
+	__ATTR(cursor_blink_ms, S_IRUGO|S_IWUSR, show_cursor_blink_ms,
+	       store_cursor_blink_ms),
 };
 
 static int fbcon_init_device(void)
-- 
2.1.4

Re: [RFC PATCH 2/2] fbcon: expose cursor blink interval via sysfs

[Geert Uytterhoeven]

On Sat, Jan 24, 2015 at 2:19 AM, Scot Doyle <lkml14@scotdoyle.com> wrote:
> +static ssize_t store_cursor_blink_ms(struct device *device,
> +                                    struct device_attribute *attr,
> +                                    const char *buf, size_t count)
> +{

...

> +       unsigned long ms;

...

> +       if (!kstrtoul(buf, 0, &ms)) {

kstrtos16()?

> +               ms = min_t(unsigned long, ms, SHRT_MAX);
> +               ops->blink_jiffies = max_t(int, msecs_to_jiffies(ms), 1);


Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

[PATCH v2 1/2] fbcon: store cursor blink interval in fbcon_ops

[Scot Doyle]

The fbcon cursor, when set to blink, is hardcoded to toggle display state
five times per second. Move this setting to a the driver's fbdev_ops
structure, retaining the default blink interval.

Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
---
 drivers/video/console/fbcon.c | 5 +++--
 drivers/video/console/fbcon.h | 1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index ea43724..7a2030b 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -405,7 +405,7 @@ static void cursor_timer_handler(unsigned long dev_addr)
 	struct fbcon_ops *ops = info->fbcon_par;
 
 	queue_work(system_power_efficient_wq, &info->queue);
-	mod_timer(&ops->cursor_timer, jiffies + HZ/5);
+	mod_timer(&ops->cursor_timer, jiffies + ops->blink_jiffies);
 }
 
 static void fbcon_add_cursor_timer(struct fb_info *info)
@@ -420,7 +420,7 @@ static void fbcon_add_cursor_timer(struct fb_info *info)
 
 		init_timer(&ops->cursor_timer);
 		ops->cursor_timer.function = cursor_timer_handler;
-		ops->cursor_timer.expires = jiffies + HZ / 5;
+		ops->cursor_timer.expires = jiffies + ops->blink_jiffies;
 		ops->cursor_timer.data = (unsigned long ) info;
 		add_timer(&ops->cursor_timer);
 		ops->flags |= FBCON_FLAGS_CURSOR_TIMER;
@@ -959,6 +959,7 @@ static const char *fbcon_startup(void)
 	ops->currcon = -1;
 	ops->graphics = 1;
 	ops->cur_rotate = -1;
+	ops->blink_jiffies = msecs_to_jiffies(200);
 	info->fbcon_par = ops;
 	p->con_rotate = initial_rotation;
 	set_blitting_type(vc, info);
diff --git a/drivers/video/console/fbcon.h b/drivers/video/console/fbcon.h
index 6bd2e0c..642c4e7 100644
--- a/drivers/video/console/fbcon.h
+++ b/drivers/video/console/fbcon.h
@@ -70,6 +70,7 @@ struct fbcon_ops {
 	struct fb_cursor cursor_state;
 	struct display *p;
         int    currcon;	                /* Current VC. */
+	int    blink_jiffies;
 	int    cursor_flash;
 	int    cursor_reset;
 	int    blank_state;
-- 
2.1.4

[PATCH v2 2/2] fbcon: expose cursor blink interval via sysfs

[Scot Doyle]

The fbcon cursor, when set to blink, is hardcoded to toggle display state
five times per second. Expose this setting via
/sys/class/graphics/fbcon/cursor_blink_ms

Values written to the interface set the approximate time interval in
milliseconds between cursor toggles, from 1 to 32767. Since the interval
is stored internally as a number of jiffies, the millisecond value read
from the interface may not exactly match the entered value.

An outstanding blink timer is reset after a new value is entered.

If the cursor blink is disabled, either via the 'cursor_blink' boolean
setting or some other mechanism, the 'cursor_blink_ms' setting may still
be modified. The new value will be used if the blink is reactivated.

Tested with intelfb.

Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
---
v2:  Use kstrtos16() instead of kstrtoul() and min_t(). Thanks Geert!

 drivers/video/console/fbcon.c | 73 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 7a2030b..7b6815d 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -3495,11 +3495,84 @@ err:
 	return count;
 }
 
+static ssize_t show_cursor_blink_ms(struct device *device,
+				    struct device_attribute *attr, char *buf)
+{
+	struct fb_info *info;
+	struct fbcon_ops *ops;
+	int idx, ms = -1;
+
+	if (fbcon_has_exited)
+		return 0;
+
+	console_lock();
+	idx = con2fb_map[fg_console];
+
+	if (idx == -1 || registered_fb[idx] == NULL)
+		goto err;
+
+	info = registered_fb[idx];
+	ops = info->fbcon_par;
+
+	if (!ops)
+		goto err;
+
+	ms = jiffies_to_msecs(ops->blink_jiffies);
+
+err:
+	console_unlock();
+	return snprintf(buf, PAGE_SIZE, "%d\n", ms);
+}
+
+static ssize_t store_cursor_blink_ms(struct device *device,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct fb_info *info;
+	struct fbcon_ops *ops;
+	int idx;
+	short ms;
+
+	if (fbcon_has_exited)
+		return count;
+
+	console_lock();
+	idx = con2fb_map[fg_console];
+
+	if (idx == -1 || registered_fb[idx] == NULL)
+		goto err;
+
+	info = registered_fb[idx];
+
+	if (!info->fbcon_par)
+		goto err;
+
+	ops = info->fbcon_par;
+
+	if (!ops)
+		goto err;
+
+	if (!kstrtos16(buf, 0, &ms)) {
+		ops->blink_jiffies = max_t(int, msecs_to_jiffies(ms), 1);
+		if (info->queue.func == fb_flashcursor &&
+		    ops->flags & FBCON_FLAGS_CURSOR_TIMER) {
+			fbcon_del_cursor_timer(info);
+			fbcon_add_cursor_timer(info);
+		}
+	}
+
+err:
+	console_unlock();
+	return count;
+}
+
 static struct device_attribute device_attrs[] = {
 	__ATTR(rotate, S_IRUGO|S_IWUSR, show_rotate, store_rotate),
 	__ATTR(rotate_all, S_IWUSR, NULL, store_rotate_all),
 	__ATTR(cursor_blink, S_IRUGO|S_IWUSR, show_cursor_blink,
 	       store_cursor_blink),
+	__ATTR(cursor_blink_ms, S_IRUGO|S_IWUSR, show_cursor_blink_ms,
+	       store_cursor_blink_ms),
 };
 
 static int fbcon_init_device(void)
-- 
2.1.4

Re: [RFC PATCH 2/2] fbcon: expose cursor blink interval via sysfs

[Tomi Valkeinen]

[-- Attachment #1: Type: text/plain, Size: 3474 bytes --]

On 24/01/15 03:19, Scot Doyle wrote:
> The fbcon cursor, when set to blink, is hardcoded to toggle display state
> five times per second. Expose this setting via
> /sys/class/graphics/fbcon/cursor_blink_ms
> 
> Values written to the interface set the approximate time interval in
> milliseconds between cursor toggles, from 1 to 32767. Since the interval
> is stored internally as a number of jiffies, the millisecond value read
> from the interface may not exactly match the entered value.
> 
> An outstanding blink timer is reset after a new value is entered.
> 
> If the cursor blink is disabled, either via the 'cursor_blink' boolean
> setting or some other mechanism, the 'cursor_blink_ms' setting may still
> be modified. The new value will be used if the blink is reactivated.
> 
> Tested with intelfb.
> 
> Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
> ---
>  drivers/video/console/fbcon.c | 75 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 75 insertions(+)
> 
> diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
> index 7a2030b..0ddfcf6 100644
> --- a/drivers/video/console/fbcon.c
> +++ b/drivers/video/console/fbcon.c
> @@ -3495,11 +3495,86 @@ err:
>  	return count;
>  }
>  
> +static ssize_t show_cursor_blink_ms(struct device *device,
> +				    struct device_attribute *attr, char *buf)
> +{
> +	struct fb_info *info;
> +	struct fbcon_ops *ops;
> +	int idx, ms = -1;
> +
> +	if (fbcon_has_exited)
> +		return 0;

Why not return an error here?

> +
> +	console_lock();
> +	idx = con2fb_map[fg_console];
> +
> +	if (idx == -1 || registered_fb[idx] == NULL)
> +		goto err;

Same here?

> +	info = registered_fb[idx];
> +	ops = info->fbcon_par;
> +
> +	if (!ops)
> +		goto err;

And here.

> +
> +	ms = jiffies_to_msecs(ops->blink_jiffies);
> +
> +err:
> +	console_unlock();
> +	return snprintf(buf, PAGE_SIZE, "%d\n", ms);
> +}
> +
> +static ssize_t store_cursor_blink_ms(struct device *device,
> +				     struct device_attribute *attr,
> +				     const char *buf, size_t count)
> +{
> +	struct fb_info *info;
> +	struct fbcon_ops *ops;
> +	int idx;
> +	unsigned long ms;
> +
> +	if (fbcon_has_exited)
> +		return count;
> +
> +	console_lock();
> +	idx = con2fb_map[fg_console];
> +
> +	if (idx == -1 || registered_fb[idx] == NULL)
> +		goto err;
> +
> +	info = registered_fb[idx];
> +
> +	if (!info->fbcon_par)
> +		goto err;
> +
> +	ops = info->fbcon_par;
> +
> +	if (!ops)
> +		goto err;

Here also all the above look like errors to me, so why not return an error?

> +
> +	if (!kstrtoul(buf, 0, &ms)) {
> +		ms = min_t(unsigned long, ms, SHRT_MAX);
> +		ops->blink_jiffies = max_t(int, msecs_to_jiffies(ms), 1);
> +
> +		if (info->queue.func == fb_flashcursor &&
> +		    ops->flags & FBCON_FLAGS_CURSOR_TIMER) {
> +			fbcon_del_cursor_timer(info);
> +			fbcon_add_cursor_timer(info);
> +		}
> +	}
> +
> +err:
> +	console_unlock();
> +	return count;
> +}
> +
>  static struct device_attribute device_attrs[] = {
>  	__ATTR(rotate, S_IRUGO|S_IWUSR, show_rotate, store_rotate),
>  	__ATTR(rotate_all, S_IWUSR, NULL, store_rotate_all),
>  	__ATTR(cursor_blink, S_IRUGO|S_IWUSR, show_cursor_blink,
>  	       store_cursor_blink),
> +	__ATTR(cursor_blink_ms, S_IRUGO|S_IWUSR, show_cursor_blink_ms,
> +	       store_cursor_blink_ms),
>  };
>  
>  static int fbcon_init_device(void)
> 



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