From owner-freebsd-arm@freebsd.org Sat Aug 29 06:34:26 2015 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id CA72E9C53F4 for ; Sat, 29 Aug 2015 06:34:26 +0000 (UTC) (envelope-from hps@selasky.org) Received: from mail.turbocat.net (heidi.turbocat.net [88.198.202.214]) (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 52E4D6C8 for ; Sat, 29 Aug 2015 06:34:25 +0000 (UTC) (envelope-from hps@selasky.org) Received: from laptop015.home.selasky.org (cm-176.74.213.204.customer.telag.net [176.74.213.204]) (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 ACE131FE023; Sat, 29 Aug 2015 08:34:22 +0200 (CEST) Subject: Re: DWC OTG TX path optimisation for 11-current To: Svatopluk Kraus References: <55A7D8CE.4020809@selasky.org> <55B23276.8090703@selasky.org> <55B73113.2020308@selasky.org> <55B8AB76.7030603@selasky.org> <55B8B297.1010008@selasky.org> <20150729154516.GH78154@funkthat.com> <55B8F5EC.2050908@selasky.org> <46ad096c958.1a82a175@mail.schwarzes.net> <55B9C3E2.5040501@selasky.org> <46ae815c7c3.447237c8@mail.schwarzes.net> <46aece00b53.3c1cdc1f@mail.schwarzes.net> <55BB2A5F.9000502@selasky.org> <46baa16c4ce.6efd29ef@mail.schwarzes.net> <55CF31A1.5080205@selasky.org> <46ce372c895.20050775@mail.schwarzes.net> <46d0a4441bb.41f6f91d@mail.schwarzes.net> <55DD5C0A.2050401@selasky.org> Cc: "freebsd-arm@freebsd.org" From: Hans Petter Selasky Message-ID: <55E152C4.7010209@selasky.org> Date: Sat, 29 Aug 2015 08:35:48 +0200 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 29 Aug 2015 06:34:27 -0000 On 08/28/15 14:27, Svatopluk Kraus wrote: > On Wed, Aug 26, 2015 at 8:26 AM, Hans Petter Selasky wrote: >> On 08/25/15 21:51, Andreas Schwarz wrote: >>> >>> On 24.08.15, Andreas Schwarz wrote: >>> >>>> With both kernels I was not able to reproduce the initial problem. >>> >>> >>> By accident, today I run again into the problem (with r287086). 8( >>> >>> Aug 25 20:27:59 pizelot kernel: smsc0: warning: Failed to write register >>> 0x114 >>> Aug 25 20:45:32 pizelot kernel: smsc0: warning: Failed to read register >>> 0x114 >>> Aug 25 20:45:32 pizelot kernel: smsc0: warning: MII is busy >>> Aug 25 20:46:08 pizelot kernel: smsc0: warning: Failed to write register >>> 0x114 >>> Aug 25 20:46:14 pizelot kernel: smsc0: warning: Failed to read register >>> 0x114 >>> Aug 25 20:46:14 pizelot kernel: smsc0: warning: MII is busy >>> Aug 25 20:46:16 pizelot kernel: smsc0: warning: Failed to write register >>> 0x114 >>> Aug 25 20:46:46 pizelot kernel: smsc0: warning: Failed to read register >>> 0x114 >>> Aug 25 20:46:46 pizelot kernel: smsc0: warning: MII is busy >>> [...] >>> >> >> It might seem like some process is using all CPU on core 0, so that USB >> doesn't get a chance to run. I would suggest maybe moving the DWC OTG fast >> IRQ handling to core #1. Is it possible you could enter kgdb, and poke >> around which fast IRQ is doing work there? >> > > Well, I finally found a courage ;) to hack dwc_otg driver to be able > to inactivate it totally after trigger is pulled. And even then, if > there was no interrupt and no timer on it, the problem survived. Thus, > I thing that the driver is out of game. However, some small chance > remains that the driver might corrupt something in kernel. But this > indirect influence is, IMO, not likely. > > My subjective observation is that the slow system response can be > caused by slow wake up from idle state. I have tried to change > scheduler from ULE to BSD one with no MII warning and everything is > okay result. And buildword was about one hour faster. Note that the > trigger is very sensitive, so it can be just because system timing and > many other things are different with different scheduler. > > Another obeservation is that in the bad system state, ipi rate is 10 > times less (2 - 3 per a second) than in normal state (about 20 per a > second) measured when system is 99% idle. > > Svata > Hi, Maybe you could try to build an RPI kernel from projects/hps_head : https://svnweb.freebsd.org/base/projects/hps_head/ And test? --HPS