From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE84FC432C2 for ; Thu, 26 Sep 2019 05:45:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA6A8206B7 for ; Thu, 26 Sep 2019 05:45:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392323AbfIZFp7 (ORCPT ); Thu, 26 Sep 2019 01:45:59 -0400 Received: from mga11.intel.com ([192.55.52.93]:52499 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725870AbfIZFp6 (ORCPT ); Thu, 26 Sep 2019 01:45:58 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Sep 2019 22:45:58 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,550,1559545200"; d="asc'?scan'208";a="189009469" Received: from pipin.fi.intel.com (HELO pipin) ([10.237.72.175]) by fmsmga008.fm.intel.com with ESMTP; 25 Sep 2019 22:45:56 -0700 From: Felipe Balbi To: David Laight , 'Mathias Nyman' , alex zheng Cc: "linux-usb\@vger.kernel.org" , "xiaowei.zheng\@dji.com" Subject: RE: BUG report: usb: dwc3: Link TRB triggered an intterupt without IOC being setted In-Reply-To: References: <87a7avh8uu.fsf@gmail.com> <106544ca-7a01-0a86-e785-c7c520ebdc4b@linux.intel.com> <5431a9df-3816-b525-c3bc-4e7462d0f38f@linux.intel.com> Date: Thu, 26 Sep 2019 08:45:52 +0300 Message-ID: <87d0fny5in.fsf@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Hi, David Laight writes: > From: Mathias Nyman >> Sent: 25 September 2019 15:48 >>=20 >> On 24.9.2019 17.45, alex zheng wrote: >> > Hi Mathias, > ... >> Logs show your transfer ring has four segments, but hardware fails to >> jump from the last segment back to first) >>=20 >> Last TRB (LINK TRB) of each segment points to the next segment, >> last segments link trb points back to first segment. >>=20 >> In your case: >> 0x1d117000 -> 0x1eb09000 -> 0x1eb0a000 -> 0x1dbda000 -> (back to 0x1d117= 000) >>=20 >> For some reason your hardware doesn't treat the last TRB at the last seg= ment >> as a LINK TRB, instead it just issues a transfer event for it, and conti= nues to >> the next address instead of jumping back to first segment: > > That could be a cache coherency (or flushing (etc)) issue. XHCI has a HW-configurable maximum number of segments in a ring. AFAICT, xhci driver doesn't take that into consideration today. Perhaps the HW in question doesn't like more than 3 segments. Mathias, what was the register to check this? Do you remember? =2D-=20 balbi --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEElLzh7wn96CXwjh2IzL64meEamQYFAl2MUJAACgkQzL64meEa mQbp7RAA29UhryY8ZvesqrBPLKC0YqDrnqshqI4lAIWNaGoceXtglXKBI0sP7a7R PR1otqYYRPQ08HZdcssrb+0/JUqN1254diTxGWiWKfRDh0XUCVO9ltobxL+nAK5H 52kgCHUIFb/+wnpYcBb8PZgvucXiHYyokVzdQTkw9h3hwlURM12zhnu2KhJyLjHM V08LJcyKU8jJM9yFOhygVNTBLHKeBITKHXgCSCxUwKUIg6cdmFv8IQvdn+ypIbBC 2hkbt3IjWPy4RI5+YS+JpB2HlnLb9TWjKM1xXtma6deBRApD2in7o1As7APGbq+Z NZjlhAUgc7cGc7N0xjofaxaaYHPxnjc3cmE/2PIcntfazAe90Z2sRMK6S+SJ0E4j iUYnqAQg4x9dlm7Np9U+L0Vd9C1TAvrPS4Q+X19grvD6Lb2BGjh0CDH7UbYkefhH yLhExhk2Ir2C1kN/cdw6HC7uKj2MSpm42/x61/Gx1i2NWp0Hv7T4jfKrCr2x/hBZ MLDAxHIyKFfcVbuNPBH8pyG22VqSAeLHgDDIsu4RwPKUugiVWsZjTFf5eS0fzeAs iiacktq1G6nbiJn6yHd2mu0skQ0EZJze65+AOAO+L7iRdsc0kKl6zbk7UHmo8gKP YQ5qeXahUTYGHXVYG8UbCHMOie5hVX7zkaarWLwYqARbCSQ/51s= =o8PF -----END PGP SIGNATURE----- --=-=-=--