[PATCH] drm: mali-dp: Log internal errors v2

Alexandru Gheorghe alexandru-cosmin.gheorghe at arm.com
Fri Feb 23 10:13:42 UTC 2018


Status register contains a lot of bits for reporting internal errors
inside Mali DP. Currently, we just silently ignore all of the erorrs,
that doesn't help when we are investigating different bugs, especially
on the FPGA models which have a lot of constrains, so we could easily
end up in AXI or underrun errors.

Add a new KConfig option called CONFIG_DRM_MALI_DISPLAY_DEBUG, which
enables the logging of the errors present in the status register.

Errors will be reported in  /sys/kernel/debug/tracing/trace,
still not noisy enough, but better than silently ignoring them.

E.g:
<idle>-0     [000] d.h1  2387.240042: malidp_de_irq: error occurred at vblank 596 DE_STATUS is 0x00000001
<idle>-0     [000] d.h1  2387.256703: malidp_de_irq: error occurred at vblank 597 DE_STATUS is 0x00000001
<idle>-0     [000] d.h1  2387.273458: malidp_de_irq: error occurred at vblank 598 DE_STATUS is 0x00000001
<idle>-0     [000] d.h1  2387.290035: malidp_de_irq: error occurred at vblank 599 DE_STATUS is 0x00000001

In addition to that, I removed the setting of MALIDP550_SE_IRQ_AXI_ERR
bit in the irq_mask, since that bit doesn't exist.

v2: Consistently refer the hardware as Mali DP.

Acked-by: Liviu Dudau <liviu.dudau at arm.com>
Signed-off-by: Alexandru Gheorghe <Alexandru-Cosmin.Gheorghe at arm.com>
---
 drivers/gpu/drm/arm/Kconfig       | 10 +++++++++
 drivers/gpu/drm/arm/malidp_hw.c   | 45 ++++++++++++++++++++++++++++++++-------
 drivers/gpu/drm/arm/malidp_hw.h   |  1 +
 drivers/gpu/drm/arm/malidp_regs.h |  6 ++++++
 4 files changed, 54 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/arm/Kconfig b/drivers/gpu/drm/arm/Kconfig
index 9a18e1b..46e95b2 100644
--- a/drivers/gpu/drm/arm/Kconfig
+++ b/drivers/gpu/drm/arm/Kconfig
@@ -40,3 +40,13 @@ config DRM_MALI_DISPLAY
 	  of the hardware.
 
 	  If compiled as a module it will be called mali-dp.
+
+config DRM_MALI_DISPLAY_DEBUG
+	bool "Enable Mali DP debugging"
+	default n
+	depends on DRM_MALI_DISPLAY
+	select FTRACE
+	help
+	  Enable this option to log internal errors that happened during
+	  processing of a frame. Errors will be reported in
+	  /sys/kernel/debug/tracing/trace.
diff --git a/drivers/gpu/drm/arm/malidp_hw.c b/drivers/gpu/drm/arm/malidp_hw.c
index 2bfb542..7d3b2e2 100644
--- a/drivers/gpu/drm/arm/malidp_hw.c
+++ b/drivers/gpu/drm/arm/malidp_hw.c
@@ -632,10 +632,16 @@ const struct malidp_hw malidp_device[MALIDP_MAX_DEVICES] = {
 					    MALIDP500_DE_IRQ_VSYNC |
 					    MALIDP500_DE_IRQ_GLOBAL,
 				.vsync_irq = MALIDP500_DE_IRQ_VSYNC,
+				.err_mask = MALIDP_DE_IRQ_UNDERRUN |
+					    MALIDP500_DE_IRQ_AXI_ERR |
+					    MALIDP500_DE_IRQ_SATURATION,
 			},
 			.se_irq_map = {
 				.irq_mask = MALIDP500_SE_IRQ_CONF_MODE,
 				.vsync_irq = 0,
+				.err_mask = MALIDP500_SE_IRQ_INIT_BUSY |
+					    MALIDP500_SE_IRQ_AXI_ERROR |
+					    MALIDP500_SE_IRQ_OVERRUN,
 			},
 			.dc_irq_map = {
 				.irq_mask = MALIDP500_DE_IRQ_CONF_VALID,
@@ -669,10 +675,15 @@ const struct malidp_hw malidp_device[MALIDP_MAX_DEVICES] = {
 				.irq_mask = MALIDP_DE_IRQ_UNDERRUN |
 					    MALIDP550_DE_IRQ_VSYNC,
 				.vsync_irq = MALIDP550_DE_IRQ_VSYNC,
+				.err_mask = MALIDP_DE_IRQ_UNDERRUN |
+					    MALIDP550_DE_IRQ_SATURATION |
+					    MALIDP550_DE_IRQ_AXI_ERR,
 			},
 			.se_irq_map = {
-				.irq_mask = MALIDP550_SE_IRQ_EOW |
-					    MALIDP550_SE_IRQ_AXI_ERR,
+				.irq_mask = MALIDP550_SE_IRQ_EOW,
+				.err_mask  = MALIDP550_SE_IRQ_AXI_ERR |
+					     MALIDP550_SE_IRQ_OVR |
+					     MALIDP550_SE_IRQ_IBSY,
 			},
 			.dc_irq_map = {
 				.irq_mask = MALIDP550_DC_IRQ_CONF_VALID,
@@ -707,10 +718,20 @@ const struct malidp_hw malidp_device[MALIDP_MAX_DEVICES] = {
 					    MALIDP650_DE_IRQ_DRIFT |
 					    MALIDP550_DE_IRQ_VSYNC,
 				.vsync_irq = MALIDP550_DE_IRQ_VSYNC,
+				.err_mask = MALIDP_DE_IRQ_UNDERRUN |
+					    MALIDP650_DE_IRQ_DRIFT |
+					    MALIDP550_DE_IRQ_SATURATION |
+					    MALIDP550_DE_IRQ_AXI_ERR |
+					    MALIDP650_DE_IRQ_ACEV1 |
+					    MALIDP650_DE_IRQ_ACEV2 |
+					    MALIDP650_DE_IRQ_ACEG |
+					    MALIDP650_DE_IRQ_AXIEP,
 			},
 			.se_irq_map = {
-				.irq_mask = MALIDP550_SE_IRQ_EOW |
-					    MALIDP550_SE_IRQ_AXI_ERR,
+				.irq_mask = MALIDP550_SE_IRQ_EOW,
+				.err_mask = MALIDP550_SE_IRQ_AXI_ERR |
+					    MALIDP550_SE_IRQ_OVR |
+					    MALIDP550_SE_IRQ_IBSY,
 			},
 			.dc_irq_map = {
 				.irq_mask = MALIDP550_DC_IRQ_CONF_VALID,
@@ -793,10 +814,15 @@ static irqreturn_t malidp_de_irq(int irq, void *arg)
 		return ret;
 
 	mask = malidp_hw_read(hwdev, MALIDP_REG_MASKIRQ);
-	status &= mask;
+	/* keep the status of the enabled interrupts, plus the error bits */
+	status &= (mask | de->err_mask);
 	if (status & de->vsync_irq)
 		drm_crtc_handle_vblank(&malidp->crtc);
-
+#ifdef CONFIG_DRM_MALI_DISPLAY_DEBUG
+	if (status & de->err_mask)
+		trace_printk("error occurred at vblank %llu DE_STATUS is 0x%08X\n",
+			     drm_crtc_vblank_count(&malidp->crtc), status);
+#endif
 	malidp_hw_clear_irq(hwdev, MALIDP_DE_BLOCK, status);
 
 	return (ret == IRQ_NONE) ? IRQ_HANDLED : ret;
@@ -874,9 +900,12 @@ static irqreturn_t malidp_se_irq(int irq, void *arg)
 	status = malidp_hw_read(hwdev, hw->map.se_base + MALIDP_REG_STATUS);
 	if (!(status & se->irq_mask))
 		return IRQ_NONE;
-
+#ifdef CONFIG_DRM_MALI_DISPLAY_DEBUG
+	if (status & se->err_mask)
+		trace_printk("error occurred at vblank %llu SE_STATUS is 0x%08X\n",
+			     drm_crtc_vblank_count(&malidp->crtc), status);
+#endif
 	mask = malidp_hw_read(hwdev, hw->map.se_base + MALIDP_REG_MASKIRQ);
-	status = malidp_hw_read(hwdev, hw->map.se_base + MALIDP_REG_STATUS);
 	status &= mask;
 	/* ToDo: status decoding and firing up of VSYNC and page flip events */
 
diff --git a/drivers/gpu/drm/arm/malidp_hw.h b/drivers/gpu/drm/arm/malidp_hw.h
index b0690eb..909b76e 100644
--- a/drivers/gpu/drm/arm/malidp_hw.h
+++ b/drivers/gpu/drm/arm/malidp_hw.h
@@ -52,6 +52,7 @@ struct malidp_format_id {
 struct malidp_irq_map {
 	u32 irq_mask;		/* mask of IRQs that can be enabled in the block */
 	u32 vsync_irq;		/* IRQ bit used for signaling during VSYNC */
+	u32 err_mask;		/* mask of bits in status register that represent errors */
 };
 
 struct malidp_layer {
diff --git a/drivers/gpu/drm/arm/malidp_regs.h b/drivers/gpu/drm/arm/malidp_regs.h
index 2039f85..ec53811 100644
--- a/drivers/gpu/drm/arm/malidp_regs.h
+++ b/drivers/gpu/drm/arm/malidp_regs.h
@@ -53,6 +53,8 @@
 #define MALIDP550_DE_IRQ_AXI_ERR		(1 << 16)
 #define MALIDP550_SE_IRQ_EOW			(1 << 0)
 #define MALIDP550_SE_IRQ_AXI_ERR		(1 << 16)
+#define MALIDP550_SE_IRQ_OVR			(1 << 17)
+#define MALIDP550_SE_IRQ_IBSY			(1 << 18)
 #define MALIDP550_DC_IRQ_CONF_VALID		(1 << 0)
 #define MALIDP550_DC_IRQ_CONF_MODE		(1 << 4)
 #define MALIDP550_DC_IRQ_CONF_ACTIVE		(1 << 16)
@@ -60,6 +62,10 @@
 #define MALIDP550_DC_IRQ_SE			(1 << 24)
 
 #define MALIDP650_DE_IRQ_DRIFT			(1 << 4)
+#define MALIDP650_DE_IRQ_ACEV1			(1 << 17)
+#define MALIDP650_DE_IRQ_ACEV2			(1 << 18)
+#define MALIDP650_DE_IRQ_ACEG			(1 << 19)
+#define MALIDP650_DE_IRQ_AXIEP			(1 << 28)
 
 /* bit masks that are common between products */
 #define   MALIDP_CFG_VALID		(1 << 0)
-- 
2.7.4



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