[i-g-t V2 2/5] lib/drrs: Add support to force drrs to default on exit

[Bhanuprakash Modem <bhanuprakash.modem@intel.com>]

Use existing exit handler helpers to reset the drrs status
to default on exit.

Signed-off-by: Bhanuprakash Modem <bhanuprakash.modem@intel.com>
---
 lib/i915/intel_drrs.c | 41 ++++++++++++++++++++++-------------------
 lib/igt_kms.c         | 20 ++++++++++++++++++++
 lib/igt_kms.h         |  3 +++
 3 files changed, 45 insertions(+), 19 deletions(-)

diff --git a/lib/i915/intel_drrs.c b/lib/i915/intel_drrs.c
index ac8dd5e61..0d1f9cbad 100644
--- a/lib/i915/intel_drrs.c
+++ b/lib/i915/intel_drrs.c
@@ -56,26 +56,18 @@ bool intel_output_has_drrs(int device, igt_output_t *output)
 	return strstr(buf, "seamless");
 }
 
-static void drrs_set(int device, enum pipe pipe, unsigned int val)
+static void reset_crtc_drrs_at_exit(int sig)
 {
-	char buf[2];
-	int dir, ret;
-
-	igt_debug("Manually %sabling DRRS. %u\n", val ? "en" : "dis", val);
-	snprintf(buf, sizeof(buf), "%d", val);
+	igt_reset_crtcs();
+}
 
-	dir = igt_debugfs_pipe_dir(device, pipe, O_DIRECTORY);
-	igt_require_fd(dir);
-	ret = igt_sysfs_write(dir, "i915_drrs_ctl", buf, sizeof(buf) - 1);
-	close(dir);
+static bool drrs_set(int device, enum pipe pipe, const char *val)
+{
+	igt_debug("Manually %sabling DRRS.\n", !strcmp(val, "1") ? "en" : "dis");
 
-	/*
-	 * drrs_enable() is called on DRRS capable platform only,
-	 * whereas drrs_disable() is called on all platforms.
-	 * So handle the failure of debugfs_write only for drrs_enable().
-	 */
-	if (val)
-		igt_assert_f(ret == (sizeof(buf) - 1), "debugfs_write failed");
+	return igt_set_crtc_attrs(device, pipe,
+				  "i915_drrs_ctl",
+				  val, "0");
 }
 
 /**
@@ -90,7 +82,17 @@ static void drrs_set(int device, enum pipe pipe, unsigned int val)
  */
 void intel_drrs_enable(int device, enum pipe pipe)
 {
-	drrs_set(device, pipe, 1);
+	bool ret = drrs_set(device, pipe, "1");
+
+	/*
+	 * drrs_enable() is called on DRRS capable platform only,
+	 * whereas drrs_disable() is called on all platforms.
+	 * So handle the failure of debugfs_write only for drrs_enable().
+	 */
+	igt_assert_f(ret == 1, "debugfs_write failed");
+
+	dump_crtc_attrs();
+	igt_install_exit_handler(reset_crtc_drrs_at_exit);
 }
 
 /**
@@ -105,7 +107,8 @@ void intel_drrs_enable(int device, enum pipe pipe)
  */
 void intel_drrs_disable(int device, enum pipe pipe)
 {
-	drrs_set(device, pipe, 0);
+	drrs_set(device, pipe, "0");
+	dump_crtc_attrs();
 }
 
 /**
diff --git a/lib/igt_kms.c b/lib/igt_kms.c
index c22cdb602..d7f6e475e 100644
--- a/lib/igt_kms.c
+++ b/lib/igt_kms.c
@@ -1912,6 +1912,26 @@ static bool crtc_attr_set_debugfs(int drm_fd, enum pipe pipe,
 	return true;
 }
 
+/**
+ * igt_set_crtc_attrs:
+ * @drm_fd: drm file descriptor
+ * @pipe: pipe
+ * @attr: attribute to set
+ * @value: value to set
+ * @reset_value: value to reset to
+ *
+ * Set the attribute @attr to @value on the crtc-@pipe.
+ *
+ * @return: true on success
+ */
+bool igt_set_crtc_attrs(int drm_fd, enum pipe pipe,
+			const char *attr, const char *value,
+			const char *reset_value)
+{
+	return crtc_attr_set_debugfs(drm_fd, pipe, attr, value, reset_value);
+
+}
+
 /**
  * kmstest_set_connector_dpms:
  *
diff --git a/lib/igt_kms.h b/lib/igt_kms.h
index 97efbefa5..67635d89a 100644
--- a/lib/igt_kms.h
+++ b/lib/igt_kms.h
@@ -1085,6 +1085,9 @@ void igt_pipe_refresh(igt_display_t *display, enum pipe pipe, bool force);
 void igt_enable_connectors(int drm_fd);
 void igt_reset_connectors(void);
 
+bool igt_set_crtc_attrs(int drm_fd, enum pipe pipe,
+			const char *attr, const char *value,
+			const char *reset_value);
 void igt_reset_crtcs(void);
 void dump_crtc_attrs(void);
 
-- 
2.43.0