This adds some basic helpers for connecting to udev and watching for
sysfs hotplug events.
Cc: Tomeu Vizoso <tomeu@xxxxxxxxxxxxxxx>
Signed-off-by: Lyude <lyude@xxxxxxxxxx>
Changes since v1:
- Remove unused arg from documentation
Changes since v2:
- Make udev_monitor explicit so that we can use this for detecting FSMs
from the Chamelium in rpc calls
---
lib/igt_kms.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
lib/igt_kms.h | 7 ++++
2 files changed, 118 insertions(+)
diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index d104734..e36c0b8 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -38,6 +38,10 @@
#elif HAVE_SYS_KD_H
#include <sys/kd.h>
#endif
+#ifdef HAVE_UDEV
+#include <libudev.h>
+#include <poll.h>
+#endif
#include <errno.h>
#include <time.h>
@@ -2921,6 +2925,113 @@ void igt_reset_connectors(void)
"detect");
}
+#ifdef HAVE_UDEV
+
+/**
+ * igt_watch_hotplug:
+ *
+ * Begin monitoring udev for sysfs hotplug events.
+ *
+ * Returns: a udev monitor for detecting hotplugs on
+ */
+struct udev_monitor *igt_watch_hotplug(void)
+{
+ struct udev *udev;
+ struct udev_monitor *mon;
+ int ret, flags, fd;
+
+ udev = udev_new();
+ igt_assert(udev != NULL);
+
+ mon = udev_monitor_new_from_netlink(udev, "udev");
+ igt_assert(mon != NULL);
+
+ ret = udev_monitor_filter_add_match_subsystem_devtype(mon,
+ "drm",
+ "drm_minor");
+ igt_assert_eq(ret, 0);
+ ret = udev_monitor_filter_update(mon);
+ igt_assert_eq(ret, 0);
+ ret = udev_monitor_enable_receiving(mon);
+ igt_assert_eq(ret, 0);
+
+ /* Set the fd for udev as non blocking */
+ fd = udev_monitor_get_fd(mon);
+ flags = fcntl(fd, F_GETFL, 0);
+ igt_assert(flags);
+
+ flags |= O_NONBLOCK;
+ igt_assert_neq(fcntl(fd, F_SETFL, flags), -1);
+
+ return mon;
+}
+
+/**
+ * igt_hotplug_detected:
+ * @mon: A udev monitor initialized with #igt_watch_hotplug
+ * @timeout_secs: How long to wait for a hotplug event to occur.
+ *
+ * Assert that a hotplug event was received since we last checked the monitor.
+ *
+ * Returns: true if a sysfs hotplug event was received, false if we timed out
+ */
+bool igt_hotplug_detected(struct udev_monitor *mon, int timeout_secs)
+{
+ struct udev_device *dev;
+ const char *hotplug_val;
+ struct pollfd fd = {
+ .fd = udev_monitor_get_fd(mon),
+ .events = POLLIN
+ };
+ bool hotplug_received = false;
+
+ /* Go through all of the events pending on the udev monitor. Once we
+ * receive a hotplug, we continue going through the rest of the events
+ * so that redundant hotplug events don't change the results of future
+ * checks
+ */
+ while (!hotplug_received && poll(&fd, 1, timeout_secs * 1000)) {
+ dev = udev_monitor_receive_device(mon);
+
+ hotplug_val = udev_device_get_property_value(dev, "HOTPLUG");
+ if (hotplug_val && atoi(hotplug_val) == 1)
+ hotplug_received = true;
+
+ udev_device_unref(dev);
+ }
+
+ return hotplug_received;
+}
+
+/**
+ * igt_flush_hotplugs:
+ * @mon: A udev monitor initialized with #igt_watch_hotplug
+ *
+ * Get rid of any pending hotplug events
+ */
+void igt_flush_hotplugs(struct udev_monitor *mon)
+{
+ struct udev_device *dev;
+
+ while ((dev = udev_monitor_receive_device(mon)))
+ udev_device_unref(dev);
+}
+
+/**
+ * igt_cleanup_hotplug:
+ *
+ * Cleanup the resources allocated by #igt_watch_hotplug
+ */
+void igt_cleanup_hotplug(struct udev_monitor *mon)
+{
+ struct udev *udev = udev_monitor_get_udev(mon);
+
+ udev_monitor_unref(mon);
+ mon = NULL;
+ udev_unref(udev);
+}
+#endif
+
/**
* kmstest_get_vbl_flag:
* @pipe_id: Pipe to convert to flag representation.
diff --git a/lib/igt_kms.h b/lib/igt_kms.h
index 64414a2..53cc900 100644
--- a/lib/igt_kms.h
+++ b/lib/igt_kms.h
@@ -503,5 +503,12 @@ uint32_t kmstest_get_vbl_flag(uint32_t pipe_id);
const unsigned char* igt_kms_get_base_edid(void);
const unsigned char* igt_kms_get_alt_edid(void);
+#ifdef HAVE_UDEV
+struct udev_monitor *igt_watch_hotplug(void);
+bool igt_hotplug_detected(struct udev_monitor *mon,
+ int timeout_secs);
+void igt_flush_hotplugs(struct udev_monitor *mon);
+void igt_cleanup_hotplug(struct udev_monitor *mon);
+#endif
#endif /* __IGT_KMS_H__ */
--
2.9.3
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