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From:   Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date:   Mon, 1 Jul 2019 19:54:15 +0200
Message-ID: <CAFBinCDDyG_CxW+PB_OrUXfy-aDKSoewC2OyCfGh18N=omSgcQ@mail.gmail.com>
Subject: Re: [PATCH] usb: dwc2: use a longer AHB idle timeout in dwc2_core_reset()
To:     "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "felipe.balbi@linux.intel.com" <felipe.balbi@linux.intel.com>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc:     Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        linux-stable <stable@vger.kernel.org>
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On Mon, Jun 24, 2019 at 7:41 AM Minas Harutyunyan
<Minas.Harutyunyan@synopsys.com> wrote:
>
> On 6/20/2019 9:51 PM, Martin Blumenstingl wrote:
> > Use a 10000us AHB idle timeout in dwc2_core_reset() and make it
> > consistent with the other "wait for AHB master IDLE state" ocurrences.
> >
> > This fixes a problem for me where dwc2 would not want to initialize when
> > updating to 4.19 on a MIPS Lantiq VRX200 SoC. dwc2 worked fine with
> > 4.14.
> > Testing on my board shows that it takes 180us until AHB master IDLE
> > state is signalled. The very old vendor driver for this SoC (ifxhcd)
> > used a 1 second timeout.
> > Use the same timeout that is used everywhere when polling for
> > GRSTCTL_AHBIDLE instead of using a timeout that "works for one board"
> > (180us in my case) to have consistent behavior across the dwc2 driver.
> >
> > Cc: linux-stable <stable@vger.kernel.org> # 4.19+
> > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> > ---
>
> Acked-by: Minas Harutyunyan <hminas@synopsys.com>
thank you for reviewing this!

is there any chance we can get this fix into Linux 5.3? I know that
it's too late for 5.2 so I'm fine with skipping that.


Martin