linux-kernel - [PATCH v2 1/2] drm/v3d: fix client obtained from axi

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Message-ID: <20250425122522.18425-1-jmcasanova@igalia.com>
Date: Fri, 25 Apr 2025 14:25:07 +0200
From: Jose Maria Casanova Crespo <jmcasanova@...lia.com>
To: Melissa Wen <mwen@...lia.com>,
	Maíra Canal <mcanal@...lia.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Simona Vetter <simona@...ll.ch>,
	Paul Kocialkowski <paul.kocialkowski@...tlin.com>
Cc: Jose Maria Casanova Crespo <jmcasanova@...lia.com>,
	dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org,
	kernel-dev@...lia.com
Subject: [PATCH v2 1/2] drm/v3d: fix client obtained from axi_ids on V3D 4.1

In the case of MMU errors caused by the TFU unit, the
client that causes the MMU error is expected to be reported.
But in the case of MMU TFU errors, a non existing client was
being reported. This happened because the client calculation
was taking into account more than the bits 0-7 from the
axi_id that were representing the client.

[   27.845132] v3d fec00000.v3d: MMU error from client ? (13) at 0x3bb1000, pte invalid

Masking the bits and using the correct exi_id ranges fixes the
calculation to report the real guilty client on V3D 4.1 and 4.2.

Make the MMU error print axi_id with hexadecimal as used in the
ranges.

Fixes: 38c2c7917adc ("drm/v3d: Fix and extend MMU error handling.")
Signed-off-by: Jose Maria Casanova Crespo <jmcasanova@...lia.com>
---
 drivers/gpu/drm/v3d/v3d_irq.c | 37 +++++++++++++++++++++++------------
 1 file changed, 24 insertions(+), 13 deletions(-)

Changes in v2:
- Now axi_id is showed in hexadecimal in error message (Maira Canal)
- Improved commit log description with error example. (Maira Canal)
- Fixed typos in commit log (Maira Canal)

diff --git a/drivers/gpu/drm/v3d/v3d_irq.c b/drivers/gpu/drm/v3d/v3d_irq.c
index 29f63f572d35..d6ce1324905d 100644
--- a/drivers/gpu/drm/v3d/v3d_irq.c
+++ b/drivers/gpu/drm/v3d/v3d_irq.c
@@ -186,27 +186,38 @@ v3d_hub_irq(int irq, void *arg)
 		u32 axi_id = V3D_READ(V3D_MMU_VIO_ID);
 		u64 vio_addr = ((u64)V3D_READ(V3D_MMU_VIO_ADDR) <<
 				(v3d->va_width - 32));
-		static const char *const v3d41_axi_ids[] = {
-			"L2T",
-			"PTB",
-			"PSE",
-			"TLB",
-			"CLE",
-			"TFU",
-			"MMU",
-			"GMP",
+		static const struct {
+			u32 begin;
+			u32 end;
+			const char *client;
+		} v3d41_axi_ids[] = {
+			{0x00, 0x20, "L2T"},
+			{0x20, 0x21, "PTB"},
+			{0x40, 0x41, "PSE"},
+			{0x60, 0x80, "TLB"},
+			{0x80, 0x88, "CLE"},
+			{0xA0, 0xA1, "TFU"},
+			{0xC0, 0xE0, "MMU"},
+			{0xE0, 0xE1, "GMP"},
 		};
 		const char *client = "?";
 
 		V3D_WRITE(V3D_MMU_CTL, V3D_READ(V3D_MMU_CTL));
 
 		if (v3d->ver >= V3D_GEN_41) {
-			axi_id = axi_id >> 5;
-			if (axi_id < ARRAY_SIZE(v3d41_axi_ids))
-				client = v3d41_axi_ids[axi_id];
+			size_t i;
+
+			axi_id = axi_id & 0xFF;
+			for (i = 0; i < ARRAY_SIZE(v3d41_axi_ids); i++) {
+				if (axi_id >= v3d41_axi_ids[i].begin &&
+				    axi_id < v3d41_axi_ids[i].end) {
+					client = v3d41_axi_ids[i].client;
+					break;
+				}
+			}
 		}
 
-		dev_err(v3d->drm.dev, "MMU error from client %s (%d) at 0x%llx%s%s%s\n",
+		dev_err(v3d->drm.dev, "MMU error from client %s (0x%x) at 0x%llx%s%s%s\n",
 			client, axi_id, (long long)vio_addr,
 			((intsts & V3D_HUB_INT_MMU_WRV) ?
 			 ", write violation" : ""),
-- 
2.49.0