[v4,0/2] Add SMI reset and clamp for MediaTek MT8188 SoC

Message

Friday Yang Feb. 21, 2025, 7:48 a.m. UTC

Based on tag: next-20250220, linux-next/master

On the MediaTek MT8188 SoC platform, we encountered power-off failures
and SMI bus hang issues during camera stress tests. The issue arises
because bus glitches are sometimes produced when MTCMOS powers on or
off. While this is fairly normal, the software must handle these
glitches to avoid mistaking them for transaction signals. What's
more, this issue emerged only after the initial upstreaming of SMI
driver.

The software solutions can be summarized as follows:

1. Use CLAMP to disable the SMI sub-common port after turning off the
   LARB CG and before turning off the LARB MTCMOS.
2. Use CLAMP to disable/enable the SMI sub-common port.
3. Implement an AXI reset for SMI LARBs.

Changes v4:
- Use 'devm_reset_control_get_optional_exclusive' instead of
  'devm_reset_control_get'.

v3:
https://lore.kernel.org/lkml/20250121064934.13482-2-
[e-mail]/
https://lore.kernel.org/lkml/20250121064934.13482-3-
[e-mail]/

friday.yang (2):
  dt-bindings: memory: mediatek: Add SMI reset and clamp for MT8188
  memory: mtk-smi: mt8188: Add SMI reset and clamp for MT8188

 .../mediatek,smi-common.yaml                  |   2 +
 .../memory-controllers/mediatek,smi-larb.yaml |  20 +++
 drivers/memory/mtk-smi.c                      | 141 +++++++++++++++++-
 3 files changed, 159 insertions(+), 4 deletions(-)

--
2.46.0

Comments

Krzysztof Kozlowski Feb. 22, 2025, 9:45 a.m. UTC | #1

On Fri, Feb 21, 2025 at 03:48:30PM +0800, Friday Yang wrote:
> Based on tag: next-20250220, linux-next/master
> 
> On the MediaTek MT8188 SoC platform, we encountered power-off failures
> and SMI bus hang issues during camera stress tests. The issue arises
> because bus glitches are sometimes produced when MTCMOS powers on or
> off. While this is fairly normal, the software must handle these
> glitches to avoid mistaking them for transaction signals. What's
> more, this issue emerged only after the initial upstreaming of SMI
> driver.
> 
> The software solutions can be summarized as follows:
> 
> 1. Use CLAMP to disable the SMI sub-common port after turning off the
>    LARB CG and before turning off the LARB MTCMOS.
> 2. Use CLAMP to disable/enable the SMI sub-common port.
> 3. Implement an AXI reset for SMI LARBs.
> 
> Changes v4:
> - Use 'devm_reset_control_get_optional_exclusive' instead of
>   'devm_reset_control_get'.
> 
> v3:
> https://lore.kernel.org/lkml/20250121064934.13482-2-

That's not a valid link. Fix your email client.

Best regards,
Krzysztof