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From: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>
To: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>,
	Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>,
	robh@kernel.org, vkoul@kernel.org
Cc: krzk+dt@kernel.org, conor+dt@kernel.org, srini@kernel.org,
	yung-chuan.liao@linux.intel.com,
	prasad.kumpatla@oss.qualcomm.com, jingyi.wang@oss.qualcomm.com,
	sibi.sankar@oss.qualcomm.com, quic_srivasam@quicinc.com,
	linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-sound@vger.kernel.org
Subject: Re: [PATCH v2 2/3] soundwire: qcom: add multi-master support
Date: Thu, 1 Oct 2026 12:06:29 +0100	[thread overview]
Message-ID: <586046f1-8439-4353-b60d-dab6356de3ba@oss.qualcomm.com> (raw)
In-Reply-To: <0ca6ee6a-020a-4705-8323-d524a813d3b5@linux.dev>



On 10/1/26 11:53 AM, Pierre-Louis Bossart wrote:
> 
>> @@ -192,6 +194,13 @@ struct qcom_swrm_ctrl {
>>  	const unsigned int *reg_layout;
>>  	void __iomem *mmio;
>>  	struct reset_control *audio_cgcr;
>> +	u8 num_lanes;
>> +	bool is_dependent;
>> +	struct qcom_swrm_ctrl *peer_ctrl;
>> +	u8 peer_first_lane;
>> +	u8 num_peer_lanes;
>> +	bool is_primary;
>> +	u32 peer_dpn_offset;
> 
> nit-pick: do you need both is_dependent and is_primary? One would think
> that a single variable would be enough, no?
I did try to do that which made the code bit confusing to read.


> 
> also without context it's hard to understand if lanes are independent in
> terms of transport or not, not sure what 'peer' means in a multi-master
> setup with a primary controller and N dependent ones? Code like this
For now its one, but Yes, technically we could have more dependent ones,
I wanted to keep the patchset simple and right now the only have one
peer and i dont know if we have other setups with more dependent
controrllers.
--srini

> function below is a bit cryptic...
> 
>> +static struct qcom_swrm_ctrl *
>> +qcom_swrm_port_target(struct qcom_swrm_ctrl *ctrl, u8 port_num, u32 *reg)
>> +{
>> +	u8 lane = ctrl->pconfig[port_num].lane_control;
>> +
>> +	if (ctrl->peer_ctrl && lane >= ctrl->peer_first_lane &&
>> +	    lane < ctrl->peer_first_lane + ctrl->num_peer_lanes) {
>> +		*reg -= ctrl->peer_dpn_offset;
>> +		return ctrl->peer_ctrl;
>> +	}
>> +	return ctrl;
>> +}
> 
> 


  reply	other threads:[~2026-10-01 11:06 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-10-01  9:38 [PATCH v2 0/3] " Srinivas Kandagatla
2026-10-01  9:38 ` [PATCH v2 1/3] dt-bindings: soundwire: qcom: describe multi-master Srinivas Kandagatla
2026-10-01  9:38 ` [PATCH v2 2/3] soundwire: qcom: add multi-master support Srinivas Kandagatla
2026-10-01 10:53   ` Pierre-Louis Bossart
2026-10-01 11:06     ` Srinivas Kandagatla [this message]
2026-10-01  9:38 ` [PATCH v2 3/3] soundwire: qcom: program MM_SYNC for multi-master Srinivas Kandagatla

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