Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757188AbcLPLrP (ORCPT ); Fri, 16 Dec 2016 06:47:15 -0500 Received: from mga02.intel.com ([134.134.136.20]:65509 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934635AbcLPLrG (ORCPT ); Fri, 16 Dec 2016 06:47:06 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.33,357,1477983600"; d="asc'?scan'208";a="1082634465" From: Felipe Balbi To: Jerry Huang , "gregkh\@linuxfoundation.org" Cc: "linux-usb\@vger.kernel.org" , "linux-kernel\@vger.kernel.org" , Rajesh Bhagat Subject: RE: [PATCH] USB3/DWC3: Enable undefined length INCR burst type In-Reply-To: References: <1481619983-4782-1-git-send-email-jerry.huang@nxp.com> <87k2b0fd2z.fsf@linux.intel.com> Date: Fri, 16 Dec 2016 13:44:10 +0200 Message-ID: <87bmwcf69h.fsf@linux.intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2522 Lines: 76 --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Hi, Jerry Huang writes: >> there's no need for that. This patch is in good format. I do have a ques= tion, >> however: how do you know this will work for all users? Burst size is a f= unction >> of how wide the interconnect where dwc3 is attached to, is. > So I need to generate one new property in usb node to identify my platfor= m? Well, we probably need a property to be passed, yes. But let's go through it all first :-) >> You could very well be degrading performance for some users here. Can you >> send me the result of the following commands *without* this patch applie= d? >>=20 >> # mkdir -p /d >> # mount -t debugfs none /d >> # cat /d/*dwc3*/regdump >>=20 > Below is the regdump: > root@ls1043ardb:/d/3000000.usb3# cat regdump > GSBUSCFG0 =3D 0x00100080 so you already have INCR256 here. There's one note in the databook which just caught my attention. It states the following: "Undefined burst length has priority over all other burst lenghts." This means that setting both INCR16 and undefined INCR is unnecessary. Only Undefined INCR will be taken into consideration. Can you check with your HW engineers what's the largest burst the interconnect is supposed to support? > GSBUSCFG1 =3D 0x00000700 8 AXI pipelined requests > GSNPSID =3D 0x5533280a 2.80a cool :-) I'll check these settings on my platform as well and see if there's any setting which would improve transfer speed. This is a very good idea, btw, but we need to be careful about how to play with it. =2D-=20 balbi --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEElLzh7wn96CXwjh2IzL64meEamQYFAlhT04oACgkQzL64meEa mQZBRxAAskKH7oBsw5vgH85sOzPTZMzUD+oXInY9dSi275Dm9TD4nMpaLKI2L7rv USA7a9zHiJ8OLlZV1U3h7qMlm6MVohWxrDFWu/Mj2pfneFckwpZ3xvyRpAxFt5K1 BMxuwTd1bl1KSJoyfYDKRy93uvN5/3cZ0FaV4KCxxDmFPqNKHVPHOw4qhg9KR6qL 0NS0D/gOfzK6kOhV+2205v/9Ko7qHEUIfApS5dpjXpxCnfrgMN2oj+uueH5HDhjh KuD6o+G1kFETFB7nM/l8/jOVUtqFHRcG5ajuZzUpeNfPJGX7+IWZB5UKWXcvSGFp 1vS3HFjsmQdxxiJQIKfvakka0I6Fk4oMefrEUBepCWr3ncsN/UMT+qj5Olo9IW/W bbp8rgEbUSXCglv203doMyVU/OBCrAlgCskJ1W0ENccqPv/7p4eUBTqNTLXf7N4+ RiwyEI8MZEWHdrjdj3S4pVP7qkmEU/TU31Bjt7Hf1sneW/FuSodLx3nDDUbRiNAy fu1aViTnWiesnWLYYR/58z22lJwKtKvzfROL3FBsDVt6KtuLk0wA86/ZtIE7uXdd qg/nA47RqQYAnzyslzC0dEykiGG2+o+KFDf1KX44xBDwEc6NEC3VZ5oUCCLs6Zff fgq9F/9PYCwsPEMMI7xziQJiPo5KEuDZfF36VtNc9+yystOdepo= =bOaQ -----END PGP SIGNATURE----- --=-=-=--