From: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
To: Neil Armstrong <neil.armstrong@linaro.org>,
Rob Clark <robin.clark@oss.qualcomm.com>,
Sean Paul <sean@poorly.run>,
Konrad Dybcio <konradybcio@kernel.org>,
Dmitry Baryshkov <lumag@kernel.org>,
Abhinav Kumar <abhinav.kumar@linux.dev>,
Jessica Zhang <jessica.zhang@oss.qualcomm.com>,
Marijn Suijten <marijn.suijten@somainline.org>,
David Airlie <airlied@gmail.com>, Simona Vetter <simona@ffwll.ch>,
Akhil P Oommen <akhilpo@oss.qualcomm.com>
Cc: linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org,
freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] drm/msm: adreno: fix deferencing ifpc_reglist when not declared
Date: Mon, 17 Nov 2025 16:02:25 +0100 [thread overview]
Message-ID: <04aec988-59ba-4c98-b922-510d86b10ea5@oss.qualcomm.com> (raw)
In-Reply-To: <20251117-topic-sm8x50-fix-a6xx-non-ifpc-v1-1-e4473cbf5903@linaro.org>
On 11/17/25 3:51 PM, Neil Armstrong wrote:
> On plaforms with an a7xx GPU not supporting IFPC, the ifpc_reglist
> if still deferenced in a7xx_patch_pwrup_reglist() which causes
> a kernel crash:
> Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008
> ...
> pc : a6xx_hw_init+0x155c/0x1e4c [msm]
> lr : a6xx_hw_init+0x9a8/0x1e4c [msm]
> ...
> Call trace:
> a6xx_hw_init+0x155c/0x1e4c [msm] (P)
> msm_gpu_hw_init+0x58/0x88 [msm]
> adreno_load_gpu+0x94/0x1fc [msm]
> msm_open+0xe4/0xf4 [msm]
> drm_file_alloc+0x1a0/0x2e4 [drm]
> drm_client_init+0x7c/0x104 [drm]
> drm_fbdev_client_setup+0x94/0xcf0 [drm_client_lib]
> drm_client_setup+0xb4/0xd8 [drm_client_lib]
> msm_drm_kms_post_init+0x2c/0x3c [msm]
> msm_drm_init+0x1a4/0x228 [msm]
> msm_drm_bind+0x30/0x3c [msm]
> ...
>
> Check the validity of ifpc_reglist before deferencing the table
> to setup the register values.
>
> Fixes: a6a0157cc68e ("drm/msm/a6xx: Enable IFPC on Adreno X1-85")
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---
I think it should be fine to skip calling this func altogether
if !ifpc || !pwrup_reglist
Although ifpc && !pwrup_reglist should probably scream very loud
Konrad
next prev parent reply other threads:[~2025-11-17 15:02 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-17 14:51 Neil Armstrong
2025-11-17 15:02 ` Konrad Dybcio [this message]
2025-11-17 15:47 ` Neil Armstrong
2025-11-18 7:47 ` Akhil P Oommen
2025-11-18 13:35 ` Konrad Dybcio
2025-11-18 7:35 ` Akhil P Oommen
2025-11-18 7:36 ` Akhil P Oommen
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