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References: <20210107224901.2102479-1-dev@kresin.me>
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From:   Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date:   Fri, 8 Jan 2021 20:48:05 +0100
Message-ID: <CAFBinCBm21ZwN2eB8pjWQivkZQp1eC_5=g9M-VwKpRtakJjnHg@mail.gmail.com>
Subject: Re: [PATCH] phy: lantiq: rcu-usb2: wait after clock enable
To:     Mathias Kresin <dev@kresin.me>
Cc:     Kishon Vijay Abraham I <kishon@ti.com>,
        Vinod Koul <vkoul@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        linux-kernel@vger.kernel.org, Hauke Mehrtens <hauke@hauke-m.de>,
        stable@vger.kernel.org
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On Thu, Jan 7, 2021 at 11:49 PM Mathias Kresin <dev@kresin.me> wrote:
>
> Commit 65dc2e725286 ("usb: dwc2: Update Core Reset programming flow.")
> revealed that the phy isn't ready immediately after enabling it's
> clocks. The dwc2_check_core_version() fails and the dwc2 usb driver
> errors out.
>
> Add a short delay to let the phy get up and running. There isn't any
> documentation how much time is required, the value was chosen based on
> tests.
>
> Cc: <stable@vger.kernel.org> # v5.7+
> Signed-off-by: Mathias Kresin <dev@kresin.me>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>