From: Tony Lindgren <tony@atomide.com>
To: Felipe Balbi <balbi@kernel.org>
Cc: Roger Quadros <rogerq@ti.com>,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-omap@vger.kernel.org
Subject: Re: [PATCH] ARM: dts: dra7: Disable USB metastability workaround for USB2
Date: Mon, 11 Dec 2017 08:47:31 -0800 [thread overview]
Message-ID: <20171211164731.GL24344@atomide.com> (raw)
In-Reply-To: <87r2sau3fo.fsf@linux.intel.com>
* Felipe Balbi <balbi@kernel.org> [171204 11:43]:
> Roger Quadros <rogerq@ti.com> writes:
>
> > The metastability workaround causes Erratic errors [1]
> > on the HighSpeed USB PHY which can cause upto 2 seconds
> > delay in enumerating to a USB host while in Gadget mode.
> >
> > Disable the Run/Stop metastability workaround to avoid this
> > ill effect. We are aware that this opens up the opportunity
> > for Run/Stop metastability, however this issue has never been
> > observed in TI releases so we think that Run/Stop metastability
> > is a lesser evil than the PHY Erratic errors. So disable it.
> >
> > [1] USB controller trace during gadget enumeration
> > irq/90-dwc3-969 [000] d... 52.323145: dwc3_event: event (00000901): Erratic Error [U0]
> > irq/90-dwc3-969 [000] d... 52.560646: dwc3_event: event (00000901): Erratic Error [U0]
> > irq/90-dwc3-969 [000] d... 52.798144: dwc3_event: event (00000901): Erratic Error [U0]
> >
> > Signed-off-by: Roger Quadros <rogerq@ti.com>
>
> FWIW:
>
> Acked-by: Felipe Balbi <felipe.balbi@linux/intel.com>
>
> I'm taking the dwc3 counterpart to v4.16
OK applying this into omap-for-v4.16/dt thanks.
Tony
prev parent reply other threads:[~2017-12-11 16:47 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-31 13:26 [PATCH] ARM: dts: dra7: Disable USB metastability workaround for USB2 Roger Quadros
2017-12-04 11:40 ` Felipe Balbi
2017-12-11 16:47 ` Tony Lindgren [this message]
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