linux-kernel - [PATCH] drm/msm/a6xx: fix bogus hwcg register updates

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Message-ID: <20251221164552.19990-1-johan@kernel.org>
Date: Sun, 21 Dec 2025 17:45:52 +0100
From: Johan Hovold <johan@...nel.org>
To: Rob Clark <robin.clark@....qualcomm.com>,
	Sean Paul <sean@...rly.run>
Cc: Konrad Dybcio <konradybcio@...nel.org>,
	Akhil P Oommen <akhilpo@....qualcomm.com>,
	Dmitry Baryshkov <lumag@...nel.org>,
	Abhinav Kumar <abhinav.kumar@...ux.dev>,
	Jessica Zhang <jesszhan0024@...il.com>,
	Marijn Suijten <marijn.suijten@...ainline.org>,
	Bjorn Andersson <andersson@...nel.org>,
	linux-arm-msm@...r.kernel.org,
	dri-devel@...ts.freedesktop.org,
	freedreno@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org,
	Johan Hovold <johan@...nel.org>,
	stable@...r.kernel.org
Subject: [PATCH] drm/msm/a6xx: fix bogus hwcg register updates

The hw clock gating register sequence consists of register value pairs
that are written to the GPU during initialisation.

The a690 hwcg sequence has two GMU registers in it that used to amount
to random writes in the GPU mapping, but since commit 188db3d7fe66
("drm/msm/a6xx: Rebase GMU register offsets") they trigger a fault as
the updated offsets now lie outside the mapping. This in turn breaks
boot of machines like the Lenovo ThinkPad X13s.

Note that the updates of these GMU registers is already taken care of
properly since commit 40c297eb245b ("drm/msm/a6xx: Set GMU CGC
properties on a6xx too"), but for some reason these two entries were
left in the table.

Fixes: 5e7665b5e484 ("drm/msm/adreno: Add Adreno A690 support")
Cc: stable@...r.kernel.org	# 6.5
Cc: Bjorn Andersson <andersson@...nel.org>
Cc: Konrad Dybcio <konradybcio@...nel.org>
Signed-off-by: Johan Hovold <johan@...nel.org>
---
 drivers/gpu/drm/msm/adreno/a6xx_catalog.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
index 29107b362346..4c2f739ee9b7 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_catalog.c
@@ -501,8 +501,6 @@ static const struct adreno_reglist a690_hwcg[] = {
 	{REG_A6XX_RBBM_CLOCK_CNTL_GMU_GX, 0x00000222},
 	{REG_A6XX_RBBM_CLOCK_DELAY_GMU_GX, 0x00000111},
 	{REG_A6XX_RBBM_CLOCK_HYST_GMU_GX, 0x00000555},
-	{REG_A6XX_GPU_GMU_AO_GMU_CGC_DELAY_CNTL, 0x10111},
-	{REG_A6XX_GPU_GMU_AO_GMU_CGC_HYST_CNTL, 0x5555},
 	{}
 };
 
-- 
2.51.2