Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.32 as permitted sender) client-ip=23.128.96.32;
Message-ID: <6d4d959c-b155-471b-b13d-f6fda557cfe0@quicinc.com>
Date:   Wed, 15 Nov 2023 23:12:16 +0530
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v13 05/10] usb: dwc3: qcom: Refactor IRQ handling in QCOM
 Glue driver
To:     Johan Hovold <johan@kernel.org>
CC:     Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        "Andy Gross" <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        "Konrad Dybcio" <konrad.dybcio@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Felipe Balbi <balbi@kernel.org>,
        Wesley Cheng <quic_wcheng@quicinc.com>,
        <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <quic_pkondeti@quicinc.com>, <quic_ppratap@quicinc.com>,
        <quic_jackp@quicinc.com>, <ahalaney@redhat.com>,
        <quic_shazhuss@quicinc.com>
References: <20231007154806.605-1-quic_kriskura@quicinc.com>
 <20231007154806.605-6-quic_kriskura@quicinc.com>
 <ZTJ_T1UL8-s2cgNz@hovoldconsulting.com>
 <14fc724c-bc99-4b5d-9893-3e5eff8895f7@quicinc.com>
 <ZTY7Lwjd3_8NlfEi@hovoldconsulting.com>
 <cabf24d0-8eea-4eb5-8205-bf7fe6017ec2@quicinc.com>
 <ZTZ-EvvbuA6HpycT@hovoldconsulting.com>
 <fb5e5e1d-520c-4cbc-adde-f30e853421a1@quicinc.com>
 <ZTdqnSHq_Jo8AuPW@hovoldconsulting.com>
 <04615205-e380-4719-aff1-f32c26004b14@quicinc.com>
 <ZUz4RD3MjnLlPn6V@hovoldconsulting.com>
Content-Language: en-US
From:   Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>
In-Reply-To: <ZUz4RD3MjnLlPn6V@hovoldconsulting.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


Hi Johan,

> Are you sure there's no support for hs_phy_irq also in the "femto" PHYs
> and that it's just that there is currently no driver support for using
> them?
> 
> And why is it defined if there is truly no use for it?
> 

We had an internal sync up with HW folks and here is some baseline 
suggestions we received:

If DP/DM interrupts are defined, then that is the preferred path to 
used, irrespective if HS Phy irq is defined or not / or whether it is 
Femto / QUSB2 target. There is no target that has femto phy but misses 
DP/DM today.

For cases like sdm660/msm8998/msm8953/msm8956, these targets use 
hs_phy_irq only and don't rely on DP/DM. So we cannot remove the binding 
in entirety.

> Also, if hs_phy_irq and dp/dm_phy_irq were mutually exclusive, why does
> the following Qualcomm SoCs define all three?
> 

HS Phy Irq is redundant or functionality is mutually exclusive in this 
case. If there are targets that define all three, then we need to update 
those to only utilize DP/DM interrupts.

Regards,
Krishna,