Re: 回复: [EXT] Re: [PATCH v3 02/17] firmware: scmi: smt: Interrupt communication enable

[Marek Vasut]

On 1/6/25 7:17 AM, Alice Guo (OSS) wrote:
>> On 1/3/25 7:45 AM, Alice Guo wrote:
>>> From: Viorel Suman <viorel.suman at nxp.com>
>>>
>>> When interrupt driven communication is supported
>>
>> U-Boot does not use interrupts.
>>
>>> , the transport allows
>>> the caller to choose between interrupt and polling driven
>>> communications. To make the choice, the channel flags are used. i.MX95
>>> uses interrupt driven communication so that Channel flags should be
>>> set to 1.
>>
>> How does this work in U-Boot, which does not use interrupts ?
> 
> Hi Marek,
> 
> The clearer explanation will be added in the commit log.
> 
> This is based on Arm® System Control and Management Interface Platform Design Document Version 3.2 (Document number: DEN0056E) 5.1.2. When Bit[0] of Channel flags is 1, the System Manager runs on M core will trigger general-purpose interrupts to A core. U-Boot polls General-purpose Status (GSR) until GIPn is set.
If U-Boot does polling, why does this bit need to be set, shouldn't the 
bit be cleared instead ?