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From: Felipe Balbi <balbi@kernel.org>
To: tony@atomide.com
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-omap@vger.kernel.org, Roger Quadros <rogerq@ti.com>
Subject: Re: [PATCH] ARM: dts: dra7: Disable USB metastability workaround for USB2
Date: Mon, 04 Dec 2017 13:40:11 +0200	[thread overview]
Message-ID: <87r2sau3fo.fsf@linux.intel.com> (raw)
In-Reply-To: <1509456360-2638-1-git-send-email-rogerq@ti.com>

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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

-- 
balbi

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  reply	other threads:[~2017-12-04 11:40 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 [this message]
2017-12-11 16:47   ` Tony Lindgren

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