Description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Disable DMCUB timeout for DCN35 [Why] DMCUB can intermittently take longer than expected to process commands. Old ASIC policy was to continue while logging a diagnostic error - which works fine for ASIC without IPS, but with IPS this could lead to a race condition where we attempt to access DCN state while it's inaccessible, leading to a system hang when the NIU port is not disabled or register accesses that timeout and the display configuration in an undefined state. [How] We need to investigate why these accesses take longer than expected, but for now we should disable the timeout on DCN35 to avoid this race condition. Since the waits happen only at lower interrupt levels the risk of taking too long at higher IRQ and causing a system watchdog timeout are minimal.

Weaknesses 1

Affected Products 7

References 2

• git.kernel.org https://git.kernel.org/stable/c/31c254c9cd4b122a10db297124f867107a696d83
  Patch
• git.kernel.org https://git.kernel.org/stable/c/7c70e60fbf4bff1123f0e8d5cb1ae71df6164d7f
  Patch

Remediation

• git.kernel.org https://git.kernel.org/stable/c/31c254c9cd4b122a10db297124f867107a696d83
  Patch
• git.kernel.org https://git.kernel.org/stable/c/7c70e60fbf4bff1123f0e8d5cb1ae71df6164d7f
  Patch