On 10/21/2019 9:56 PM, Wolfram Sang wrote:
Changes I submitted in this patch set is for a different purpose which
is very Aspeed H/W specific, and actually it's a more serious timeout
setting indeed. If this H/W is used in multi-master environment, it
could meet a H/W hang that freezes itself in slave mode and it can't
escape from the state. To resolve the specific case, this H/W provides
self-recovery feature which monitors abnormal state of SDA, SCL and its
H/W state machine using the timeout setting to determine the escape
condition.
Thanks for the summary. I just wonder on what the timeout value depends.
Do we really need to put in DT or can we derive it e.g. from the
compatible value in the driver?
It could be derived from the bus timeout value by computing 'divide by
x' roughly but it couldn't cover all use cases because this H/W timeout
value would depends on each environment. There are many factors that
can affect it such as bus speed, peer-master's bus driving
characteristic, average transaction period on the bus and so on thus
it may need fine adjustments through a DT setting, I think.
Thanks,
Jae
