Re: [PATCH 6.18 085/314] media: verisilicon: Avoid G2 bus error while decoding H.264 and HEVC

Sasha Levin
2026-03-11T01:15:30Z

On Wed, Mar 11, 2026 at 01:36:46AM +0100, Sebastian Krzyszkowiak wrote:
>On wtorek, 10 marca 2026 12:15:44 czas środkowoeuropejski standardowy Sasha
>Levin wrote:
>> From: Ming Qian <ming.qian@oss.nxp.com>
>>
>> [ Upstream commit e0203ddf9af7c8e170e1e99ce83b4dc07f0cd765 ]
>>
>> For the i.MX8MQ platform, there is a hardware limitation: the g1 VPU and
>> g2 VPU cannot decode simultaneously; otherwise, it will cause below bus
>> error and produce corrupted pictures, even potentially lead to system hang.
>>
>> [ 110.527986] hantro-vpu 38310000.video-codec: frame decode timed out.
>> [ 110.583517] hantro-vpu 38310000.video-codec: bus error detected.
>>
>> Therefore, it is necessary to ensure that g1 and g2 operate alternately.
>> This allows for successful multi-instance decoding of H.264 and HEVC.
>>
>> To achieve this, g1 and g2 share the same v4l2_m2m_dev, and then the
>> v4l2_m2m_dev can handle the scheduling.
>>
>> Fixes: cb5dd5a0fa518 ("media: hantro: Introduce G2/HEVC decoder")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Ming Qian <ming.qian@oss.nxp.com>
>> Reviewed-by: Frank Li <Frank.Li@nxp.com>
>> Co-developed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
>> Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
>> Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>> ---
>> drivers/media/platform/verisilicon/hantro.h | 2 +
>> .../media/platform/verisilicon/hantro_drv.c | 42 +++++++++++++++++--
>> .../media/platform/verisilicon/imx8m_vpu_hw.c | 8 ++++
>> 3 files changed, 49 insertions(+), 3 deletions(-)
>>
>
>This one introduces a regression that's being fixed in https://lore.kernel.org/
>lkml/20260306031059.801-1-ming.qian@oss.nxp.com/T/, so they should probably be
>applied together once the fix lands.

I can drop it from 6.18<=, but note that it was already released as part of
6.19.

We can revisit a revert or cherry picking the fix for 6.19 after the current
release cycle.

--
Thanks,
Sasha