linux-kernel - [RFC] reading GPU register cause reset

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Message-ID: <CAKR_QVLvVhemt=BQ24QAvCOsR4-SEvR3p9N5xB_7=qdixVC6BA@mail.gmail.com>
Date:   Sat, 20 Oct 2018 12:54:47 +0200
From:   Tom Psyborg <pozega.tomislav@...il.com>
To:     linux-kernel@...r.kernel.org
Subject: [RFC] reading GPU register cause reset

Hi

Using 4.9.133 on RS780 chipset (HD3200) with radeon.dpm=1 setting and
noticed the following problem:

Reading gpu_reset through debug fs by issuing

sudo cat /sys/kernel/debug/dri/0/radeon_gpu_reset

causes GPU to reset and sometimes to freeze or garble screen output as
you can see on screenshot, the value returned is always 0.

Shouldn't GPU reset only on echoing 1 to this register?

Download attachment "Screenshot.png" of type "image/png" (378038 bytes)