Re: [PATCH] soundwire: SDCA: detect sdca_cascade interrupt

[Vinod Koul]

On 04-11-20, 23:23, Bard Liao wrote:
> From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
> 
> The SoundWire 1.2 specification defines an "SDCA cascade" bit which
> handles a logical OR of all SDCA interrupt sources (up to 30 defined).
> 
> Due to limitations of the addressing space, this bit is located in the
> SDW_DP0_INT register when DP0 is used, or alternatively in the
> DP0_SDCA_Support_INTSTAT register when DP0 is not used.
> 
> To allow for both cases to be handled, this bit will be checked in the
> main device-level interrupt handling code. This will result in the
> register being read twice if DP0 is enabled, but it's not clear how to
> optimize this case. It's also more logical to deal with this interrupt
> at the device than the port level, this bit is really not DP0 specific
> and its location in the DP0_INTSTAT bit is only due to the lack of
> free space in SCP_INTSTAT_1.
> 
> The SDCA_Cascade bit cannot be masked or cleared, so the interrupt
> handling only forwards the detection to the Slave driver, which will
> deal with reading the relevant SDCA status bits and clearing them. The
> bus driver only signals the detection.
> 
> The communication with the Slave driver is based on the same interrupt
> callback, with only an extension to provide the status of the
> sdca_cascade bit.

Applied, thanks

-- 
~Vinod