From owner-freebsd-usb@freebsd.org Thu May 2 10:32:39 2019 Return-Path: Delivered-To: freebsd-usb@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 2FA87158FC85 for ; Thu, 2 May 2019 10:32:39 +0000 (UTC) (envelope-from hps@selasky.org) Received: from mail.turbocat.net (turbocat.net [IPv6:2a01:4f8:c17:6c4b::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 50CD2873A7 for ; Thu, 2 May 2019 10:32:38 +0000 (UTC) (envelope-from hps@selasky.org) Received: from hps2016.home.selasky.org (unknown [176.74.212.121]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 7A25B260354; Thu, 2 May 2019 12:32:35 +0200 (CEST) Subject: Re: USB transfers in device drivers To: "O'Connor, Daniel" Cc: freebsd-usb@freebsd.org References: <3B922C60-32E5-484E-8AFA-28FF7255CF2C@dons.net.au> From: Hans Petter Selasky Message-ID: Date: Thu, 2 May 2019 12:32:07 +0200 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 50CD2873A7 X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; spf=pass (mx1.freebsd.org: domain of hps@selasky.org designates 2a01:4f8:c17:6c4b::2 as permitted sender) smtp.mailfrom=hps@selasky.org X-Spamd-Result: default: False [-5.73 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; R_SPF_ALLOW(-0.20)[+a:mail.turbocat.net]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[selasky.org]; TO_MATCH_ENVRCPT_SOME(0.00)[]; MX_GOOD(-0.01)[cached: mail.turbocat.net]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_HAM_SHORT(-0.88)[-0.884,0]; IP_SCORE(-2.53)[ip: (-8.91), ipnet: 2a01:4f8::/29(-2.06), asn: 24940(-1.69), country: DE(-0.01)]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:24940, ipnet:2a01:4f8::/29, country:DE]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-usb@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FreeBSD support for USB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 May 2019 10:32:39 -0000 On 2019-05-02 11:18, O'Connor, Daniel wrote: > OK, thanks. > To be honest I would much prefer to work out why this particular hardware & software seem to drop the ball for such a long time - 50msec without the kernel getting to schedule something (on a basically idle system) is quite perplexing to me. Sounds like a lost IRQ issue. Did you try any of the EHCI quirks in hw.usb.ehci ? --HPS