From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: [PATCH] ARM: dts: dra7: Disable USB metastability workaround for USB2 Date: Mon, 04 Dec 2017 13:40:11 +0200 Message-ID: <87r2sau3fo.fsf@linux.intel.com> References: <1509456360-2638-1-git-send-email-rogerq@ti.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Return-path: In-Reply-To: <1509456360-2638-1-git-send-email-rogerq@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: tony@atomide.com Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, Roger Quadros List-Id: linux-omap@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Roger Quadros 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 (0000090= 1): Erratic Error [U0] > irq/90-dwc3-969 [000] d... 52.560646: dwc3_event: event (0000090= 1): Erratic Error [U0] > irq/90-dwc3-969 [000] d... 52.798144: dwc3_event: event (0000090= 1): Erratic Error [U0] > > Signed-off-by: Roger Quadros FWIW: Acked-by: Felipe Balbi I'm taking the dwc3 counterpart to v4.16 =2D-=20 balbi --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEElLzh7wn96CXwjh2IzL64meEamQYFAlolNBsACgkQzL64meEa mQaJKhAAwrGW59+8FpcvEnzfxnEzF9ANszx6ncYhoBnYaJAGeAPAZOyCiyu7FCqW TBcJZLm7dVv5YATAKm6Pg5yO7164A/3A9si6D8UbxVdq702xCU3CLPNH39IoTuvT A2x6pHm6MGVcSiQ0yPrEXzv03jeViuXmFwhzqeM1mKwjcfbph4vrg82GzJ6Zv0tF BlLuU20EPnKQlKyK+XpwpeYhpyInSOe6BmCKIpEk9F+1vtz1J2b2T/DLv6OYN6Sw x7D9wYZ2NpwMtgdMMY9lG6mnA4eO8jjV2/YIa+x1u3+LdUOcd/qOxz6oWwbPhPa1 PveGgEVTT3ii8kHIHJ5oSPOCfJAuz0RETIdCWoZl98m/Y1yKNeguF90KnMQolIhg ob1aBCwT2AbVmJiOucAcuauRDPsbPXbfVBxHoVVSu+lTEww2AzR7IBNGe5xYy3Mn zaQ5Qr1zmobJ/qeLwHyZdVHeOyNYWaNtK01P8U4g2THTjGDMajx8zEuCVXLZBagW 9T+je+AIy8rLJZxj+gfLz8WXMNytggZnW40wC5rYGq58kfJAUn0LCbPqCqp4pF+t +3AybiNVXD5jdFwsf/JSwim/ocXWttLn8ikESIRY41nE179Buftd1IBxcfnxiZ3E cMHU5nHUSOZeA21KFDmtE4x0y+UASvsh4roI0chyDHtZsFf7Gjo= =DUWg -----END PGP SIGNATURE----- --=-=-=--