[PATCH] HAX drm/drm_vblank.c: Logging vblank wait queue wake up

Mohammed Khajapasha mohammed.khajapasha at intel.com
Thu Apr 9 19:14:50 UTC 2020


Logging vblank wait queue wake up event.

Test-with: 20200409072253.5216-1-mohammed.khajapasha at intel.com

Signed-off-by: Mohammed Khajapasha <mohammed.khajapasha at intel.com>
---
 drivers/gpu/drm/drm_vblank.c | 4 ++++
 kernel/printk/printk.c       | 3 ++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 1659b13b178c2..3cc25388ff471 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -1183,6 +1183,8 @@ void drm_crtc_vblank_off(struct drm_crtc *crtc)
 	if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset)
 		drm_vblank_disable_and_save(dev, pipe);
 
+	trace_printk("Waking up vblank queue before vblank off\n");
+
 	wake_up(&vblank->queue);
 
 	/*
@@ -1805,6 +1807,8 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
 
 	spin_unlock(&dev->vblank_time_lock);
 
+	trace_printk("Waking up vblank queue\n");
+
 	wake_up(&vblank->queue);
 
 	/* With instant-off, we defer disabling the interrupt until after
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index c8be5a0f52595..5946cf7ee0bef 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -454,7 +454,8 @@ static u32 clear_idx;
 
 /* record buffer */
 #define LOG_ALIGN __alignof__(struct printk_log)
-#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
+//#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
+#define __LOG_BUF_LEN (1 << 21)
 #define LOG_BUF_LEN_MAX (u32)(1 << 31)
 static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
 static char *log_buf = __log_buf;
-- 
2.24.1



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