[PATCH 0/5] drm/komeda: Improve IRQ error event prints

[PATCH 0/5] drm/komeda: Improve IRQ error event prints

[Mihail Atanassov]

Hi everyone,

This is a smallish series that tries to remove some build-time
configurability in komeda and replace it with a debugfs control. Later
patches in the series add some extra functionality which I found useful
during my debugging sessions, so I figured I'd bake it in.

I've preserved the default behaviour as if CONFIG_KOMEDA_ERROR_PRINT
were enabled, so production kernels can have some feedback from the
driver when things are going south.

1: Introduce the err_verbosity debugfs node for komeda; this keeps the
   default of printing error events once per frame.
2: Drop CONFIG_KOMEDA_ERROR_PRINT since output can be disabled at
   runtime
3: Add a drm state dump on event. It's quite chatty so I left it only
   for error events; printing all that once per frame every vsync floods my
   serial terminal, so no info + state combination.
4: Add lower-severity categories to the event printer
5: Normally these events fire only once per pageflip, but sometimes it's
   useful to see them all as they come in.

These patches are overall quite tiny, and I was considering just
squashing them into one, but I opted to keep them separate for an easier
review experience; please let me know whether you prefer a single patch.
Thanks!

Mihail Atanassov (5):
  drm/komeda: Add debugfs node to control error verbosity
  drm/komeda: Remove CONFIG_KOMEDA_ERROR_PRINT
  drm/komeda: Optionally dump DRM state on interrupts
  drm/komeda: Add option to print WARN- and INFO-level IRQ events
  drm/komeda: add rate limiting disable to err_verbosity

 drivers/gpu/drm/arm/display/Kconfig           |  6 ----
 drivers/gpu/drm/arm/display/komeda/Makefile   |  5 ++--
 .../gpu/drm/arm/display/komeda/komeda_dev.c   |  4 +++
 .../gpu/drm/arm/display/komeda/komeda_dev.h   | 30 +++++++++++++++----
 .../gpu/drm/arm/display/komeda/komeda_event.c | 24 ++++++++++++---
 .../gpu/drm/arm/display/komeda/komeda_kms.c   |  2 +-
 6 files changed, 52 insertions(+), 19 deletions(-)

-- 
2.23.0

[PATCH 1/5] drm/komeda: Add debugfs node to control error verbosity

[Mihail Atanassov]

Named 'err_verbosity', currently with only 1 active bit in that
replicates the existing level - print error events once per flip.

Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
---
 drivers/gpu/drm/arm/display/komeda/komeda_dev.c   |  4 ++++
 drivers/gpu/drm/arm/display/komeda/komeda_dev.h   | 14 ++++++++++++--
 drivers/gpu/drm/arm/display/komeda/komeda_event.c |  9 +++++++--
 drivers/gpu/drm/arm/display/komeda/komeda_kms.c   |  2 +-
 4 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
index 937a6d4c4865..82230c0ddec3 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
@@ -58,6 +58,8 @@ static void komeda_debugfs_init(struct komeda_dev *mdev)
 	mdev->debugfs_root = debugfs_create_dir("komeda", NULL);
 	debugfs_create_file("register", 0444, mdev->debugfs_root,
 			    mdev, &komeda_register_fops);
+	debugfs_create_x16("err_verbosity", 0664, mdev->debugfs_root,
+			   &mdev->err_verbosity);
 }
 #endif
 
@@ -280,6 +282,8 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
 		goto err_cleanup;
 	}
 
+	mdev->err_verbosity = KOMEDA_DEV_PRINT_ERR_EVENTS;
+
 #ifdef CONFIG_DEBUG_FS
 	komeda_debugfs_init(mdev);
 #endif
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
index 414200233b64..b5bd3d5898ee 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
@@ -202,6 +202,14 @@ struct komeda_dev {
 
 	/** @debugfs_root: root directory of komeda debugfs */
 	struct dentry *debugfs_root;
+	/**
+	 * @err_verbosity: bitmask for how much extra info to print on error
+	 *
+	 * See KOMEDA_DEV_* macros for details.
+	 */
+	u16 err_verbosity;
+	/* Print a single line per error per frame with error events. */
+#define KOMEDA_DEV_PRINT_ERR_EVENTS BIT(0)
 };
 
 static inline bool
@@ -219,9 +227,11 @@ void komeda_dev_destroy(struct komeda_dev *mdev);
 struct komeda_dev *dev_to_mdev(struct device *dev);
 
 #ifdef CONFIG_DRM_KOMEDA_ERROR_PRINT
-void komeda_print_events(struct komeda_events *evts);
+void komeda_print_events(struct komeda_events *evts, struct drm_device *dev);
 #else
-static inline void komeda_print_events(struct komeda_events *evts) {}
+static inline void komeda_print_events(struct komeda_events *evts,
+				       struct drm_device *dev)
+{}
 #endif
 
 int komeda_dev_resume(struct komeda_dev *mdev);
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_event.c b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
index a36fb86cc054..575ed4df74ed 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_event.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
@@ -107,10 +107,12 @@ static bool is_new_frame(struct komeda_events *a)
 	       (KOMEDA_EVENT_FLIP | KOMEDA_EVENT_EOW);
 }
 
-void komeda_print_events(struct komeda_events *evts)
+void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
 {
-	u64 print_evts = KOMEDA_ERR_EVENTS;
+	u64 print_evts = 0;
 	static bool en_print = true;
+	struct komeda_dev *mdev = dev->dev_private;
+	u16 const err_verbosity = mdev->err_verbosity;
 
 	/* reduce the same msg print, only print the first evt for one frame */
 	if (evts->global || is_new_frame(evts))
@@ -118,6 +120,9 @@ void komeda_print_events(struct komeda_events *evts)
 	if (!en_print)
 		return;
 
+	if (err_verbosity & KOMEDA_DEV_PRINT_ERR_EVENTS)
+		print_evts |= KOMEDA_ERR_EVENTS;
+
 	if ((evts->global | evts->pipes[0] | evts->pipes[1]) & print_evts) {
 		char msg[256];
 		struct komeda_str str;
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
index d49772de93e0..e30a5b43caa9 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
@@ -48,7 +48,7 @@ static irqreturn_t komeda_kms_irq_handler(int irq, void *data)
 	memset(&evts, 0, sizeof(evts));
 	status = mdev->funcs->irq_handler(mdev, &evts);
 
-	komeda_print_events(&evts);
+	komeda_print_events(&evts, drm);
 
 	/* Notify the crtc to handle the events */
 	for (i = 0; i < kms->n_crtcs; i++)
-- 
2.23.0

[PATCH 2/5] drm/komeda: Remove CONFIG_KOMEDA_ERROR_PRINT

[Mihail Atanassov]

Now that there's a debugfs node to control the same, remove the
config option.

Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
---
 drivers/gpu/drm/arm/display/Kconfig             | 6 ------
 drivers/gpu/drm/arm/display/komeda/Makefile     | 5 ++---
 drivers/gpu/drm/arm/display/komeda/komeda_dev.h | 6 ------
 3 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/arm/display/Kconfig b/drivers/gpu/drm/arm/display/Kconfig
index e87ff8623076..cec0639e3aa1 100644
--- a/drivers/gpu/drm/arm/display/Kconfig
+++ b/drivers/gpu/drm/arm/display/Kconfig
@@ -12,9 +12,3 @@ config DRM_KOMEDA
 	  Processor driver. It supports the D71 variants of the hardware.
 
 	  If compiled as a module it will be called komeda.
-
-config DRM_KOMEDA_ERROR_PRINT
-	bool "Enable komeda error print"
-	depends on DRM_KOMEDA
-	help
-	  Choose this option to enable error printing.
diff --git a/drivers/gpu/drm/arm/display/komeda/Makefile b/drivers/gpu/drm/arm/display/komeda/Makefile
index f095a1c68ac7..1931a7fa1a14 100644
--- a/drivers/gpu/drm/arm/display/komeda/Makefile
+++ b/drivers/gpu/drm/arm/display/komeda/Makefile
@@ -16,12 +16,11 @@ komeda-y := \
 	komeda_crtc.o \
 	komeda_plane.o \
 	komeda_wb_connector.o \
-	komeda_private_obj.o
+	komeda_private_obj.o \
+	komeda_event.o
 
 komeda-y += \
 	d71/d71_dev.o \
 	d71/d71_component.o
 
-komeda-$(CONFIG_DRM_KOMEDA_ERROR_PRINT) += komeda_event.o
-
 obj-$(CONFIG_DRM_KOMEDA) += komeda.o
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
index b5bd3d5898ee..831c375180f8 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
@@ -226,13 +226,7 @@ void komeda_dev_destroy(struct komeda_dev *mdev);
 
 struct komeda_dev *dev_to_mdev(struct device *dev);
 
-#ifdef CONFIG_DRM_KOMEDA_ERROR_PRINT
 void komeda_print_events(struct komeda_events *evts, struct drm_device *dev);
-#else
-static inline void komeda_print_events(struct komeda_events *evts,
-				       struct drm_device *dev)
-{}
-#endif
 
 int komeda_dev_resume(struct komeda_dev *mdev);
 int komeda_dev_suspend(struct komeda_dev *mdev);
-- 
2.23.0

[PATCH 3/5] drm/komeda: Optionally dump DRM state on interrupts

[Mihail Atanassov]

It's potentially useful information when diagnosing error/warn IRQs, so
dump it to dmesg with a drm_info_printer. Hide this extra debug dumping
behind another komeda_dev->err_verbosity bit.

Note that there's not much sense in dumping it for INFO events,
since the VSYNC event will swamp the log.

Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
---
 drivers/gpu/drm/arm/display/komeda/komeda_dev.h   | 5 ++++-
 drivers/gpu/drm/arm/display/komeda/komeda_event.c | 8 +++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
index 831c375180f8..4809000c1efb 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
@@ -205,11 +205,14 @@ struct komeda_dev {
 	/**
 	 * @err_verbosity: bitmask for how much extra info to print on error
 	 *
-	 * See KOMEDA_DEV_* macros for details.
+	 * See KOMEDA_DEV_* macros for details. Low byte contains the debug
+	 * level categories, the high byte contains extra debug options.
 	 */
 	u16 err_verbosity;
 	/* Print a single line per error per frame with error events. */
 #define KOMEDA_DEV_PRINT_ERR_EVENTS BIT(0)
+	/* Dump DRM state on an error or warning event. */
+#define KOMEDA_DEV_PRINT_DUMP_STATE_ON_EVENT BIT(8)
 };
 
 static inline bool
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_event.c b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
index 575ed4df74ed..5da61e7d75d5 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_event.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
@@ -4,6 +4,7 @@
  * Author: James.Qian.Wang <james.qian.wang@arm.com>
  *
  */
+#include <drm/drm_atomic.h>
 #include <drm/drm_print.h>
 
 #include "komeda_dev.h"
@@ -113,6 +114,7 @@ void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
 	static bool en_print = true;
 	struct komeda_dev *mdev = dev->dev_private;
 	u16 const err_verbosity = mdev->err_verbosity;
+	u64 evts_mask = evts->global | evts->pipes[0] | evts->pipes[1];
 
 	/* reduce the same msg print, only print the first evt for one frame */
 	if (evts->global || is_new_frame(evts))
@@ -123,9 +125,10 @@ void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
 	if (err_verbosity & KOMEDA_DEV_PRINT_ERR_EVENTS)
 		print_evts |= KOMEDA_ERR_EVENTS;
 
-	if ((evts->global | evts->pipes[0] | evts->pipes[1]) & print_evts) {
+	if (evts_mask & print_evts) {
 		char msg[256];
 		struct komeda_str str;
+		struct drm_printer p = drm_info_printer(dev->dev);
 
 		str.str = msg;
 		str.sz  = sizeof(msg);
@@ -139,6 +142,9 @@ void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
 		evt_str(&str, evts->pipes[1]);
 
 		DRM_ERROR("err detect: %s\n", msg);
+		if ((err_verbosity & KOMEDA_DEV_PRINT_DUMP_STATE_ON_EVENT)
+		    && (evts_mask & (KOMEDA_ERR_EVENTS | KOMEDA_WARN_EVENTS)))
+			drm_state_dump(dev, &p);
 
 		en_print = false;
 	}
-- 
2.23.0

[PATCH 4/5] drm/komeda: Add option to print WARN- and INFO-level IRQ events

[Mihail Atanassov]

Extra detail (normally off) almost never hurts.

Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
---
 drivers/gpu/drm/arm/display/komeda/komeda_dev.h   | 11 +++++++++++
 drivers/gpu/drm/arm/display/komeda/komeda_event.c |  4 ++++
 2 files changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
index 4809000c1efb..d9fc9c48859a 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
@@ -51,6 +51,13 @@
 
 #define KOMEDA_WARN_EVENTS	KOMEDA_ERR_CSCE
 
+#define KOMEDA_INFO_EVENTS ({0 \
+			    | KOMEDA_EVENT_VSYNC \
+			    | KOMEDA_EVENT_FLIP \
+			    | KOMEDA_EVENT_EOW \
+			    | KOMEDA_EVENT_MODE \
+			    })
+
 /* malidp device id */
 enum {
 	MALI_D71 = 0,
@@ -211,6 +218,10 @@ struct komeda_dev {
 	u16 err_verbosity;
 	/* Print a single line per error per frame with error events. */
 #define KOMEDA_DEV_PRINT_ERR_EVENTS BIT(0)
+	/* Print a single line per warning per frame with error events. */
+#define KOMEDA_DEV_PRINT_WARN_EVENTS BIT(1)
+	/* Print a single line per info event per frame with error events. */
+#define KOMEDA_DEV_PRINT_INFO_EVENTS BIT(2)
 	/* Dump DRM state on an error or warning event. */
 #define KOMEDA_DEV_PRINT_DUMP_STATE_ON_EVENT BIT(8)
 };
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_event.c b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
index 5da61e7d75d5..bf88463bb4d9 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_event.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
@@ -124,6 +124,10 @@ void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
 
 	if (err_verbosity & KOMEDA_DEV_PRINT_ERR_EVENTS)
 		print_evts |= KOMEDA_ERR_EVENTS;
+	if (err_verbosity & KOMEDA_DEV_PRINT_WARN_EVENTS)
+		print_evts |= KOMEDA_WARN_EVENTS;
+	if (err_verbosity & KOMEDA_DEV_PRINT_INFO_EVENTS)
+		print_evts |= KOMEDA_INFO_EVENTS;
 
 	if (evts_mask & print_evts) {
 		char msg[256];
-- 
2.23.0

[PATCH 5/5] drm/komeda: add rate limiting disable to err_verbosity

[Mihail Atanassov]

It's possible to get multiple events in a single frame/flip, so add an
option to print them all.

Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
---
 drivers/gpu/drm/arm/display/komeda/komeda_dev.h   | 2 ++
 drivers/gpu/drm/arm/display/komeda/komeda_event.c | 3 ++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
index d9fc9c48859a..15f52e304c08 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
@@ -224,6 +224,8 @@ struct komeda_dev {
 #define KOMEDA_DEV_PRINT_INFO_EVENTS BIT(2)
 	/* Dump DRM state on an error or warning event. */
 #define KOMEDA_DEV_PRINT_DUMP_STATE_ON_EVENT BIT(8)
+	/* Disable rate limiting of event prints (normally one per commit) */
+#define KOMEDA_DEV_PRINT_DISABLE_RATELIMIT BIT(12)
 };
 
 static inline bool
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_event.c b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
index bf88463bb4d9..86e33fed8a91 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_event.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
@@ -119,7 +119,8 @@ void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
 	/* reduce the same msg print, only print the first evt for one frame */
 	if (evts->global || is_new_frame(evts))
 		en_print = true;
-	if (!en_print)
+	if (!(err_verbosity & KOMEDA_DEV_PRINT_DISABLE_RATELIMIT)
+	    && !en_print)
 		return;
 
 	if (err_verbosity & KOMEDA_DEV_PRINT_ERR_EVENTS)
-- 
2.23.0

Re: [1/5] drm/komeda: Add debugfs node to control error verbosity

[james qian wang (Arm Technology China)]

On Mon, Oct 21, 2019 at 04:47:14PM +0000, Mihail Atanassov wrote:
> Named 'err_verbosity', currently with only 1 active bit in that
> replicates the existing level - print error events once per flip.
> 
> Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
> ---
>  drivers/gpu/drm/arm/display/komeda/komeda_dev.c   |  4 ++++
>  drivers/gpu/drm/arm/display/komeda/komeda_dev.h   | 14 ++++++++++++--
>  drivers/gpu/drm/arm/display/komeda/komeda_event.c |  9 +++++++--
>  drivers/gpu/drm/arm/display/komeda/komeda_kms.c   |  2 +-
>  4 files changed, 24 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> index 937a6d4c4865..82230c0ddec3 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
> @@ -58,6 +58,8 @@ static void komeda_debugfs_init(struct komeda_dev *mdev)
>  	mdev->debugfs_root = debugfs_create_dir("komeda", NULL);
>  	debugfs_create_file("register", 0444, mdev->debugfs_root,
>  			    mdev, &komeda_register_fops);
> +	debugfs_create_x16("err_verbosity", 0664, mdev->debugfs_root,
> +			   &mdev->err_verbosity);
>  }
>  #endif
>  
> @@ -280,6 +282,8 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
>  		goto err_cleanup;
>  	}
>  
> +	mdev->err_verbosity = KOMEDA_DEV_PRINT_ERR_EVENTS;
> +
>  #ifdef CONFIG_DEBUG_FS
>  	komeda_debugfs_init(mdev);
>  #endif
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> index 414200233b64..b5bd3d5898ee 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> @@ -202,6 +202,14 @@ struct komeda_dev {
>  
>  	/** @debugfs_root: root directory of komeda debugfs */
>  	struct dentry *debugfs_root;
> +	/**
> +	 * @err_verbosity: bitmask for how much extra info to print on error
> +	 *
> +	 * See KOMEDA_DEV_* macros for details.
> +	 */
> +	u16 err_verbosity;
> +	/* Print a single line per error per frame with error events. */
> +#define KOMEDA_DEV_PRINT_ERR_EVENTS BIT(0)
>  };
>  
>  static inline bool
> @@ -219,9 +227,11 @@ void komeda_dev_destroy(struct komeda_dev *mdev);
>  struct komeda_dev *dev_to_mdev(struct device *dev);
>  
>  #ifdef CONFIG_DRM_KOMEDA_ERROR_PRINT
> -void komeda_print_events(struct komeda_events *evts);
> +void komeda_print_events(struct komeda_events *evts, struct drm_device *dev);
>  #else
> -static inline void komeda_print_events(struct komeda_events *evts) {}
> +static inline void komeda_print_events(struct komeda_events *evts,
> +				       struct drm_device *dev)
> +{}
>  #endif
>  
>  int komeda_dev_resume(struct komeda_dev *mdev);
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_event.c b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> index a36fb86cc054..575ed4df74ed 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> @@ -107,10 +107,12 @@ static bool is_new_frame(struct komeda_events *a)
>  	       (KOMEDA_EVENT_FLIP | KOMEDA_EVENT_EOW);
>  }
>  
> -void komeda_print_events(struct komeda_events *evts)
> +void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
>  {
> -	u64 print_evts = KOMEDA_ERR_EVENTS;
> +	u64 print_evts = 0;
>  	static bool en_print = true;
> +	struct komeda_dev *mdev = dev->dev_private;
> +	u16 const err_verbosity = mdev->err_verbosity;
>  
>  	/* reduce the same msg print, only print the first evt for one frame */
>  	if (evts->global || is_new_frame(evts))
> @@ -118,6 +120,9 @@ void komeda_print_events(struct komeda_events *evts)
>  	if (!en_print)
>  		return;
>  
> +	if (err_verbosity & KOMEDA_DEV_PRINT_ERR_EVENTS)
> +		print_evts |= KOMEDA_ERR_EVENTS;
> +
>  	if ((evts->global | evts->pipes[0] | evts->pipes[1]) & print_evts) {
>  		char msg[256];
>  		struct komeda_str str;
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
> index d49772de93e0..e30a5b43caa9 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
> @@ -48,7 +48,7 @@ static irqreturn_t komeda_kms_irq_handler(int irq, void *data)
>  	memset(&evts, 0, sizeof(evts));
>  	status = mdev->funcs->irq_handler(mdev, &evts);
>  
> -	komeda_print_events(&evts);
> +	komeda_print_events(&evts, drm);
>  
>  	/* Notify the crtc to handle the events */
>  	for (i = 0; i < kms->n_crtcs; i++)

thank you for the patch, looks good to me.

BTW: for you question: 
 | These patches are overall quite tiny, and I was considering just
 | squashing them into one, but I opted to keep them separate for an easier
 | review experience; please let me know whether you prefer a single patch.

I like the current single patch. :)

Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>

Re: [2/5] drm/komeda: Remove CONFIG_KOMEDA_ERROR_PRINT

[james qian wang (Arm Technology China)]

On Mon, Oct 21, 2019 at 04:47:19PM +0000, Mihail Atanassov wrote:
> Now that there's a debugfs node to control the same, remove the
> config option.
> 
> Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
> ---
>  drivers/gpu/drm/arm/display/Kconfig             | 6 ------
>  drivers/gpu/drm/arm/display/komeda/Makefile     | 5 ++---
>  drivers/gpu/drm/arm/display/komeda/komeda_dev.h | 6 ------
>  3 files changed, 2 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/display/Kconfig b/drivers/gpu/drm/arm/display/Kconfig
> index e87ff8623076..cec0639e3aa1 100644
> --- a/drivers/gpu/drm/arm/display/Kconfig
> +++ b/drivers/gpu/drm/arm/display/Kconfig
> @@ -12,9 +12,3 @@ config DRM_KOMEDA
>  	  Processor driver. It supports the D71 variants of the hardware.
>  
>  	  If compiled as a module it will be called komeda.
> -
> -config DRM_KOMEDA_ERROR_PRINT
> -	bool "Enable komeda error print"
> -	depends on DRM_KOMEDA
> -	help
> -	  Choose this option to enable error printing.
> diff --git a/drivers/gpu/drm/arm/display/komeda/Makefile b/drivers/gpu/drm/arm/display/komeda/Makefile
> index f095a1c68ac7..1931a7fa1a14 100644
> --- a/drivers/gpu/drm/arm/display/komeda/Makefile
> +++ b/drivers/gpu/drm/arm/display/komeda/Makefile
> @@ -16,12 +16,11 @@ komeda-y := \
>  	komeda_crtc.o \
>  	komeda_plane.o \
>  	komeda_wb_connector.o \
> -	komeda_private_obj.o
> +	komeda_private_obj.o \
> +	komeda_event.o
>  
>  komeda-y += \
>  	d71/d71_dev.o \
>  	d71/d71_component.o
>  
> -komeda-$(CONFIG_DRM_KOMEDA_ERROR_PRINT) += komeda_event.o
> -
>  obj-$(CONFIG_DRM_KOMEDA) += komeda.o
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> index b5bd3d5898ee..831c375180f8 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> @@ -226,13 +226,7 @@ void komeda_dev_destroy(struct komeda_dev *mdev);
>  
>  struct komeda_dev *dev_to_mdev(struct device *dev);
>  
> -#ifdef CONFIG_DRM_KOMEDA_ERROR_PRINT
>  void komeda_print_events(struct komeda_events *evts, struct drm_device *dev);
> -#else
> -static inline void komeda_print_events(struct komeda_events *evts,
> -				       struct drm_device *dev)
> -{}
> -#endif
>

Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
>  int komeda_dev_resume(struct komeda_dev *mdev);
>  int komeda_dev_suspend(struct komeda_dev *mdev);

Re: [3/5] drm/komeda: Optionally dump DRM state on interrupts

[james qian wang (Arm Technology China)]

On Mon, Oct 21, 2019 at 04:47:24PM +0000, Mihail Atanassov wrote:
> It's potentially useful information when diagnosing error/warn IRQs, so
> dump it to dmesg with a drm_info_printer. Hide this extra debug dumping
> behind another komeda_dev->err_verbosity bit.
> 
> Note that there's not much sense in dumping it for INFO events,
> since the VSYNC event will swamp the log.
> 
> Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>

Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
> ---
>  drivers/gpu/drm/arm/display/komeda/komeda_dev.h   | 5 ++++-
>  drivers/gpu/drm/arm/display/komeda/komeda_event.c | 8 +++++++-
>  2 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> index 831c375180f8..4809000c1efb 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> @@ -205,11 +205,14 @@ struct komeda_dev {
>  	/**
>  	 * @err_verbosity: bitmask for how much extra info to print on error
>  	 *
> -	 * See KOMEDA_DEV_* macros for details.
> +	 * See KOMEDA_DEV_* macros for details. Low byte contains the debug
> +	 * level categories, the high byte contains extra debug options.
>  	 */
>  	u16 err_verbosity;
>  	/* Print a single line per error per frame with error events. */
>  #define KOMEDA_DEV_PRINT_ERR_EVENTS BIT(0)
> +	/* Dump DRM state on an error or warning event. */
> +#define KOMEDA_DEV_PRINT_DUMP_STATE_ON_EVENT BIT(8)
>  };
>  
>  static inline bool
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_event.c b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> index 575ed4df74ed..5da61e7d75d5 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> @@ -4,6 +4,7 @@
>   * Author: James.Qian.Wang <james.qian.wang@arm.com>
>   *
>   */
> +#include <drm/drm_atomic.h>
>  #include <drm/drm_print.h>
>  
>  #include "komeda_dev.h"
> @@ -113,6 +114,7 @@ void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
>  	static bool en_print = true;
>  	struct komeda_dev *mdev = dev->dev_private;
>  	u16 const err_verbosity = mdev->err_verbosity;
> +	u64 evts_mask = evts->global | evts->pipes[0] | evts->pipes[1];
>  
>  	/* reduce the same msg print, only print the first evt for one frame */
>  	if (evts->global || is_new_frame(evts))
> @@ -123,9 +125,10 @@ void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
>  	if (err_verbosity & KOMEDA_DEV_PRINT_ERR_EVENTS)
>  		print_evts |= KOMEDA_ERR_EVENTS;
>  
> -	if ((evts->global | evts->pipes[0] | evts->pipes[1]) & print_evts) {
> +	if (evts_mask & print_evts) {
>  		char msg[256];
>  		struct komeda_str str;
> +		struct drm_printer p = drm_info_printer(dev->dev);
>  
>  		str.str = msg;
>  		str.sz  = sizeof(msg);
> @@ -139,6 +142,9 @@ void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
>  		evt_str(&str, evts->pipes[1]);
>  
>  		DRM_ERROR("err detect: %s\n", msg);
> +		if ((err_verbosity & KOMEDA_DEV_PRINT_DUMP_STATE_ON_EVENT)
> +		    && (evts_mask & (KOMEDA_ERR_EVENTS | KOMEDA_WARN_EVENTS)))
> +			drm_state_dump(dev, &p);
>  
>  		en_print = false;
>  	}

Re: [4/5] drm/komeda: Add option to print WARN- and INFO-level IRQ events

[james qian wang (Arm Technology China)]

On Mon, Oct 21, 2019 at 04:47:29PM +0000, Mihail Atanassov wrote:
> Extra detail (normally off) almost never hurts.
> 
> Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>

Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
> ---
>  drivers/gpu/drm/arm/display/komeda/komeda_dev.h   | 11 +++++++++++
>  drivers/gpu/drm/arm/display/komeda/komeda_event.c |  4 ++++
>  2 files changed, 15 insertions(+)
> 
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> index 4809000c1efb..d9fc9c48859a 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> @@ -51,6 +51,13 @@
>  
>  #define KOMEDA_WARN_EVENTS	KOMEDA_ERR_CSCE
>  
> +#define KOMEDA_INFO_EVENTS ({0 \
> +			    | KOMEDA_EVENT_VSYNC \
> +			    | KOMEDA_EVENT_FLIP \
> +			    | KOMEDA_EVENT_EOW \
> +			    | KOMEDA_EVENT_MODE \
> +			    })
> +
>  /* malidp device id */
>  enum {
>  	MALI_D71 = 0,
> @@ -211,6 +218,10 @@ struct komeda_dev {
>  	u16 err_verbosity;
>  	/* Print a single line per error per frame with error events. */
>  #define KOMEDA_DEV_PRINT_ERR_EVENTS BIT(0)
> +	/* Print a single line per warning per frame with error events. */
> +#define KOMEDA_DEV_PRINT_WARN_EVENTS BIT(1)
> +	/* Print a single line per info event per frame with error events. */
> +#define KOMEDA_DEV_PRINT_INFO_EVENTS BIT(2)
>  	/* Dump DRM state on an error or warning event. */
>  #define KOMEDA_DEV_PRINT_DUMP_STATE_ON_EVENT BIT(8)
>  };
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_event.c b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> index 5da61e7d75d5..bf88463bb4d9 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> @@ -124,6 +124,10 @@ void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
>  
>  	if (err_verbosity & KOMEDA_DEV_PRINT_ERR_EVENTS)
>  		print_evts |= KOMEDA_ERR_EVENTS;
> +	if (err_verbosity & KOMEDA_DEV_PRINT_WARN_EVENTS)
> +		print_evts |= KOMEDA_WARN_EVENTS;
> +	if (err_verbosity & KOMEDA_DEV_PRINT_INFO_EVENTS)
> +		print_evts |= KOMEDA_INFO_EVENTS;
>  
>  	if (evts_mask & print_evts) {
>  		char msg[256];

Re: [5/5] drm/komeda: add rate limiting disable to err_verbosity

[james qian wang (Arm Technology China)]

On Mon, Oct 21, 2019 at 04:47:35PM +0000, Mihail Atanassov wrote:
> It's possible to get multiple events in a single frame/flip, so add an
> option to print them all.
> 
> Signed-off-by: Mihail Atanassov <mihail.atanassov@arm.com>
Reviewed-by: James Qian Wang (Arm Technology China) <james.qian.wang@arm.com>
> ---
>  drivers/gpu/drm/arm/display/komeda/komeda_dev.h   | 2 ++
>  drivers/gpu/drm/arm/display/komeda/komeda_event.c | 3 ++-
>  2 files changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> index d9fc9c48859a..15f52e304c08 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
> @@ -224,6 +224,8 @@ struct komeda_dev {
>  #define KOMEDA_DEV_PRINT_INFO_EVENTS BIT(2)
>  	/* Dump DRM state on an error or warning event. */
>  #define KOMEDA_DEV_PRINT_DUMP_STATE_ON_EVENT BIT(8)
> +	/* Disable rate limiting of event prints (normally one per commit) */
> +#define KOMEDA_DEV_PRINT_DISABLE_RATELIMIT BIT(12)
>  };
>  
>  static inline bool
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_event.c b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> index bf88463bb4d9..86e33fed8a91 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_event.c
> @@ -119,7 +119,8 @@ void komeda_print_events(struct komeda_events *evts, struct drm_device *dev)
>  	/* reduce the same msg print, only print the first evt for one frame */
>  	if (evts->global || is_new_frame(evts))
>  		en_print = true;
> -	if (!en_print)
> +	if (!(err_verbosity & KOMEDA_DEV_PRINT_DISABLE_RATELIMIT)
> +	    && !en_print)
>  		return;
>  
>  	if (err_verbosity & KOMEDA_DEV_PRINT_ERR_EVENTS)