From: Elson Serrao <elson.serrao@oss.qualcomm.com>
To: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>,
Bjorn Andersson <andersson@kernel.org>,
Conor Dooley <conor+dt@kernel.org>,
Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Konrad Dybcio <konradybcio@kernel.org>,
Krzysztof Kozlowski <krzk+dt@kernel.org>,
Rob Herring <robh@kernel.org>
Cc: linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
Peter Chen <peter.chen@kernel.org>
Subject: Re: [PATCH v7 6/8] usb: misc: qcom_eud: add role-based EUD control
Date: Wed, 9 Sep 2026 18:37:14 -0700 [thread overview]
Message-ID: <2ea2d992-d14d-4b26-91f3-c36a87acf82a@oss.qualcomm.com> (raw)
In-Reply-To: <f23595ab-e0ef-40d8-998b-4cb0426ec166@oss.qualcomm.com>
On 9/1/2026 4:36 AM, Konrad Dybcio wrote:
> On 8/31/26 5:01 AM, Elson Serrao wrote:
>> EUD functions by presenting itself as a USB device to the host PC and is
>> therefore only applicable when the port operates in device role. Keeping
>> EUD enabled in other roles provides no benefit and unnecessarily keeps
>> the associated PHY resources enabled. Furthermore, enabling EUD in host
>> role can cause the USB controller to misbehave because the EUD hub
>> supports only a single upstream-facing port.
>
> [...]
>
>> struct eud_chip *chip = dev_get_drvdata(dev);
>> + struct eud_path *path;
>> bool enable;
>> int ret;
>>
>> if (kstrtobool(buf, &enable))
>> return -EINVAL;
>>
>> + guard(mutex)(&chip->state_lock);
>
> GPT suggests port_store() should also take this lock.. I think that's
> a valid concern
>
Thanks for the review, and apologies for the delayed response.
I'll address this as well as the other relevant feedback from Sashiko in v8.
Thanks,
Elson
next prev parent reply other threads:[~2026-09-10 1:37 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-31 3:01 [PATCH v7 0/8] Improve Qualcomm EUD driver and platform support Elson Serrao
2026-08-31 3:01 ` [PATCH v7 1/8] dt-bindings: soc: qcom: eud: Add per-path child nodes for UTMI routing Elson Serrao
2026-08-31 22:39 ` Bjorn Andersson
2026-08-31 3:01 ` [PATCH v7 2/8] usb: misc: qcom_eud: add sysfs attribute for port selection Elson Serrao
2026-08-31 3:01 ` [PATCH v7 3/8] usb: misc: qcom_eud: add per-path High-Speed PHY control Elson Serrao
2026-08-31 3:01 ` [PATCH v7 4/8] usb: misc: qcom_eud: add per-path role switch support Elson Serrao
2026-08-31 3:01 ` [PATCH v7 5/8] usb: misc: qcom_eud: improve enable_store API Elson Serrao
2026-08-31 3:01 ` [PATCH v7 6/8] usb: misc: qcom_eud: add role-based EUD control Elson Serrao
2026-09-01 11:36 ` Konrad Dybcio
2026-09-10 1:37 ` Elson Serrao [this message]
2026-08-31 3:01 ` [PATCH v7 7/8] usb: misc: qcom_eud: fix virtual attach/detach event handling Elson Serrao
2026-08-31 3:01 ` [PATCH v7 8/8] arm64: dts: qcom: kodiak: Desribe EUD UTMI routing and connector mapping Elson Serrao
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