From owner-freebsd-hackers@freebsd.org Mon Jan 13 14:53:31 2020 Return-Path: Delivered-To: freebsd-hackers@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 84BF1226E7D for ; Mon, 13 Jan 2020 14:53:31 +0000 (UTC) (envelope-from hps@selasky.org) Received: from mail.turbocat.net (turbocat.net [IPv6:2a01:4f8:c17:6c4b::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 47xGmp4FSYz4cTD for ; Mon, 13 Jan 2020 14:53:30 +0000 (UTC) (envelope-from hps@selasky.org) Received: from hps2020.home.selasky.org (unknown [62.141.129.235]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id D680926032A; Mon, 13 Jan 2020 15:53:28 +0100 (CET) Subject: Re: raspberry pi zero and SLOW USB HID To: Wojciech Puchar Cc: freebsd-hackers@freebsd.org References: <9f8ae63f-abe5-27d9-e6bf-3d0cc1d3d4f3@selasky.org> From: Hans Petter Selasky Message-ID: <9a1a3901-ce03-d445-dd9e-bbd775f5288a@selasky.org> Date: Mon, 13 Jan 2020 15:52:17 +0100 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 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: 47xGmp4FSYz4cTD X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; 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 [-4.94 / 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:c]; 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)[]; RCPT_COUNT_TWO(0.00)[2]; IP_SCORE(-2.64)[ip: (-9.20), ipnet: 2a01:4f8::/29(-2.46), asn: 24940(-1.50), country: DE(-0.02)]; 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-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Jan 2020 14:53:31 -0000 On 2020-01-13 15:44, Wojciech Puchar wrote: >> >> Can you check the USB speed used between PC and RPI-zero ? Is one >> perhaps High-Speed, while the other is, Full-Speed? >> >> If yes, try to connect a high-speed USB hub in between. >> >> Output from: >> usbconfig >> >> >> You can also check using "usbdump -i usbus0 -s 65536" to see the >> actual timing of the commands. >> Hi, I think I understand now. > device is the same hardware with the same firmware. What causes larger > delays? What you see is likely a manifestion of: #define DWC_OTG_HOST_TIMER_RATE 10 /* ms */ Which is because we want save a little power polling the DWC OTG. To avoid this: USB transfers must be double buffered! That means you must submit two IN-endpoint jobs, instead of just one. Then the driver will understand there is more work to do, and not go to idlewait! --HPS