On Tue, 11 Mar 2025 20:23:21 +0800, Friday Yang wrote: > From: "Friday Yang" <friday.yang@xxxxxxxxxxxx> > > On the MediaTek platform, some SMI LARBs are directly connected to > the SMI Common, while others are connected to the SMI Sub-Common, > which in turn is connected to the SMI Common. The hardware block > diagram can be described as follows. > > SMI-Common(Smart Multimedia Interface Common) > | > +----------------+------------------+ > | | | > | | | > | | | > | | | > | | | > larb0 SMI-Sub-Common0 SMI-Sub-Common1 > | | | | | > larb1 larb2 larb3 larb7 larb9 > > For previous discussion on the direction of the code modifications, > please refer to: > https://lore.kernel.org/all/CAFGrd9qZhObQXvm2_abqaX83xMLqxjQETB2=wXpobDWU1CnvkA@xxxxxxxxxxxxxx/ > https://lore.kernel.org/all/CAPDyKFpokXV2gJDgowbixTvOH_5VL3B5H8eyhP+KJ5Fasm2rFg@xxxxxxxxxxxxxx/ > > 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 this > binding. Without these patches, the SMI becomes unstable during camera > stress tests. > > 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. > > This patch primarily add two changes: > 1. Add compatible for SMI sub-common on MT8188 SoC. > 2. Add 'resets' and 'reset-names' properties for SMI LARBs to > support SMI reset operations. > > Signed-off-by: Friday Yang <friday.yang@xxxxxxxxxxxx> > --- > .../mediatek,smi-common.yaml | 2 ++ > .../memory-controllers/mediatek,smi-larb.yaml | 19 +++++++++++++++++++ > 2 files changed, 21 insertions(+) > Acked-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
