drm/radeon: insist on 32-bit DMA for Cedar on PPC64/PPC64LE
authorBen Crocker <bcrocker@redhat.com>
Thu, 22 Feb 2018 22:52:19 +0000 (17:52 -0500)
committerAlex Deucher <alexander.deucher@amd.com>
Tue, 27 Feb 2018 04:09:38 +0000 (23:09 -0500)
commitbcb0b981c5571744ac446a6c906aa05a28d21446
treeb3c398b388bcd999cc4b652d9571c622c11d7c94
parent421334a8476fe53b147139e1221cf7b368dd7c6e
drm/radeon: insist on 32-bit DMA for Cedar on PPC64/PPC64LE

In radeon_device_init, set the need_dma32 flag for Cedar chips
(e.g. FirePro 2270).  This fixes, or at least works around, a bug
on PowerPC exposed by last year's commits

8e3f1b1d8255105f31556aacf8aeb6071b00d469 (Russell Currey)

and

253fd51e2f533552ae35a0c661705da6c4842c1b (Alistair Popple)

which enabled the 64-bit DMA iommu bypass.

This caused the device to freeze, in some cases unrecoverably, and is
the subject of several bug reports internal to Red Hat.

Signed-off-by: Ben Crocker <bcrocker@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
drivers/gpu/drm/radeon/radeon_device.c