[igt-dev] [PATCH i-g-t] lib/igt_debugfs: set provision to ignore long HPDs

[Vinod Govindapillai]

Add provision to ignore long HPDs as some displays generate
long HPDs even while connected. Setting to ignore the long
HPDs to avoid unexpected CI execution issues

Signed-off-by: Vinod Govindapillai <vinod.govindapillai at intel.com>
---
 lib/igt_debugfs.c | 22 ++++++++++++++++++++++
 lib/igt_debugfs.h |  1 +
 lib/igt_kms.c     |  3 +++
 3 files changed, 26 insertions(+)

diff --git a/lib/igt_debugfs.c b/lib/igt_debugfs.c
index a56688a5..92ce52dd 100644
--- a/lib/igt_debugfs.c
+++ b/lib/igt_debugfs.c
@@ -713,6 +713,28 @@ void igt_require_hpd_storm_ctl(int drm_fd)
 	close(fd);
 }
 
+/**
+ * igt_ignore_long_hpd:
+ *
+ * Set / unset ignore long HPD events from the panels. Some panels
+ * generate long HPDs even while connected to the ports causing
+ * unexpected CI execution issues. Set this to ignore such unexpected
+ * long HPDs where we dont expect to disconnect the displays.
+ */
+void igt_ignore_long_hpd(int drm_fd, bool enable)
+{
+	int fd = igt_debugfs_open(drm_fd, "i915_ignore_long_hpd", O_WRONLY);
+
+	if (fd < 0) {
+		igt_debug("couldn't open ignore long hpd file\n");
+		return;
+	}
+
+	igt_assert_eq(write(fd, enable ? "1" : "0", 1), 1);
+
+	close(fd);
+}
+
 static igt_pipe_crc_t *
 pipe_crc_new(int fd, enum pipe pipe, const char *source, int flags)
 {
diff --git a/lib/igt_debugfs.h b/lib/igt_debugfs.h
index 37e85067..50f5e00f 100644
--- a/lib/igt_debugfs.h
+++ b/lib/igt_debugfs.h
@@ -129,6 +129,7 @@ void igt_hpd_storm_set_threshold(int fd, unsigned int threshold);
 void igt_hpd_storm_reset(int fd);
 bool igt_hpd_storm_detected(int fd);
 void igt_require_hpd_storm_ctl(int fd);
+void igt_ignore_long_hpd(int fd, bool enable);
 
 /*
  * Drop caches
diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index 665594aa..2db4e5fa 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -2356,6 +2356,9 @@ void igt_display_require(igt_display_t *display, int drm_fd)
 	display->drm_fd = drm_fd;
 	is_i915_dev = is_i915_device(drm_fd);
 
+	/* Ignore the long HPDs */
+	igt_ignore_long_hpd(display->drm_fd, true);
+
 	drmSetClientCap(drm_fd, DRM_CLIENT_CAP_WRITEBACK_CONNECTORS, 1);
 
 	resources = drmModeGetResources(display->drm_fd);
-- 
2.34.1