On 11/15/16 21:41, Hans Verkuil wrote:
Hi Philipp,
On 11/15/2016 07:24 PM, Philipp Zabel wrote:
Hi Hans,
Am Montag, den 14.11.2016, 16:22 +0100 schrieb Hans Verkuil:
From: Hans Verkuil hans.verkuil@cisco.com
Add support for HDMI hotplug and EDID notifiers, which is used to convey information from HDMI drivers to their CEC and audio counterparts.
Based on an earlier version from Russell King:
https://patchwork.kernel.org/patch/9277043/
The hdmi_notifier is a reference counted object containing the HDMI state of an HDMI device.
When a new notifier is registered the current state will be reported to that notifier at registration time.
Signed-off-by: Hans Verkuil hans.verkuil@cisco.com
drivers/video/Kconfig | 3 + drivers/video/Makefile | 1 + drivers/video/hdmi-notifier.c | 136 ++++++++++++++++++++++++++++++++++++++++++ include/linux/hdmi-notifier.h | 43 +++++++++++++ 4 files changed, 183 insertions(+) create mode 100644 drivers/video/hdmi-notifier.c create mode 100644 include/linux/hdmi-notifier.h
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 3c20af9..1ee7b9f 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -36,6 +36,9 @@ config VIDEOMODE_HELPERS config HDMI bool
+config HDMI_NOTIFIERS
- bool
if VT source "drivers/video/console/Kconfig" endif diff --git a/drivers/video/Makefile b/drivers/video/Makefile index 9ad3c17..65f5649 100644 --- a/drivers/video/Makefile +++ b/drivers/video/Makefile @@ -1,5 +1,6 @@ obj-$(CONFIG_VGASTATE) += vgastate.o obj-$(CONFIG_HDMI) += hdmi.o +obj-$(CONFIG_HDMI_NOTIFIERS) += hdmi-notifier.o
obj-$(CONFIG_VT) += console/ obj-$(CONFIG_LOGO) += logo/ diff --git a/drivers/video/hdmi-notifier.c b/drivers/video/hdmi-notifier.c new file mode 100644 index 0000000..c2a4f1b --- /dev/null +++ b/drivers/video/hdmi-notifier.c @@ -0,0 +1,136 @@ +#include <linux/export.h> +#include <linux/hdmi-notifier.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/list.h>
+struct hdmi_notifiers {
- struct list_head head;
- struct device *dev;
- struct hdmi_notifier *n;
+};
This struct is not used, can be removed.
Indeed.
+static LIST_HEAD(hdmi_notifiers); +static DEFINE_MUTEX(hdmi_notifiers_lock);
+struct hdmi_notifier *hdmi_notifier_get(struct device *dev) +{
- struct hdmi_notifier *n;
- mutex_lock(&hdmi_notifiers_lock);
- list_for_each_entry(n, &hdmi_notifiers, head) {
if (n->dev == dev) {mutex_unlock(&hdmi_notifiers_lock);kref_get(&n->kref);return n;}- }
- n = kzalloc(sizeof(*n), GFP_KERNEL);
- if (!n)
goto unlock;- mutex_init(&n->lock);
- BLOCKING_INIT_NOTIFIER_HEAD(&n->notifiers);
- kref_init(&n->kref);
- n->dev = dev;
Currently n->dev is never set, so every caller of this function gets its own hdmi_notifier.
Oops! Well, I did say it was compile-tested only :-)
- list_add_tail(&n->head, &hdmi_notifiers);
+unlock:
- mutex_unlock(&hdmi_notifiers_lock);
- return n;
+} +EXPORT_SYMBOL_GPL(hdmi_notifier_get);
+static void hdmi_notifier_release(struct kref *kref) +{
- struct hdmi_notifier *n =
container_of(kref, struct hdmi_notifier, kref);
I also forgot to remove this notifier from the global list.
I've updated my git branch to fix this.
Hans