From nobody Sat Jan 6 23:44:49 2024 X-Original-To: freebsd-arm@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4T6xl74K60z55qRp for ; Sat, 6 Jan 2024 23:45:07 +0000 (UTC) (envelope-from saper@saper.info) Received: from q.saper.info (q.saper.info [IPv6:2605:2700:0:2:a800:ff:fec7:5c61]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature ECDSA (P-384) client-digest SHA384) (Client CN "q.saper.info", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4T6xl71lmgz4VH0 for ; Sat, 6 Jan 2024 23:45:06 +0000 (UTC) (envelope-from saper@saper.info) Authentication-Results: mx1.freebsd.org; none Received: from q.saper.info (localhost [127.0.0.1]) by q.saper.info (8.17.1/8.17.1) with ESMTPS id 406NioNY067547 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO); Sat, 6 Jan 2024 23:44:50 GMT (envelope-from saper@saper.info) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=saper.info; s=Sep2014; t=1704584690; bh=xdDObhjHhNwi2Am11GKO/gzbwNz8sRmqGX2T6uXJQG8=; h=Date:From:To:cc:Subject:In-Reply-To:References; b=SiKQu10BOxt0zJrAmtuO1EAB8MPJcz6Cg4Yvr4CLKv2BJS4hx6YmoLOHl6JFWDSCp ZBRF2iyqQ9bridRzPeEieExKbQPRQwxUuIyYANv9lb9iW+8U5MzHWwZ59qT2MHP3AI zh7MVI3DVybEsKc0JklyUVpHL8fUMykrUa4OhAww= Received: from localhost (saper@localhost) by q.saper.info (8.17.1/8.17.1/Submit) with ESMTP id 406NinJ2067544; Sat, 6 Jan 2024 23:44:50 GMT (envelope-from saper@saper.info) X-Authentication-Warning: q.saper.info: saper owned process doing -bs Date: Sat, 6 Jan 2024 23:44:49 +0000 From: Marcin Cieslak To: bob prohaska cc: Mark Millard , John F Carr , ticso@cicely.de, freebsd-arm Subject: Re: USB-serial adapter suggestions needed In-Reply-To: <849BD5E3-4C09-46CB-932D-ADC1B45F3C73@yahoo.com> Message-ID: <6s123oq9-qo39-rpqq-4q91-p6r3946003p9@fncre.vasb> References: <9o7q7p36-o7pn-27o9-62no-8p1r6o127123@fncre.vasb> <849BD5E3-4C09-46CB-932D-ADC1B45F3C73@yahoo.com> List-Id: Porting FreeBSD to ARM processors List-Archive: https://lists.freebsd.org/archives/freebsd-arm List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-arm@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed X-Rspamd-Queue-Id: 4T6xl71lmgz4VH0 X-Spamd-Bar: ---- X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:47066, ipnet:2605:2700::/32, country:US] On Fri, 5 Jan 2024, Mark Millard wrote: > I also request to again list the exact content of the two > config.txt files --and again every time they are changed during > this investigation. I second this. There is way too much text in this conversation and not enough data. It also does not help if every system is somewhat different. >> To all appearances, the troublemaker is powerd. > > I'd word it that powerd activity is involved --but is unlikely to > be the only activity involved in the bad interaction(s). Lack of > powerd activity (fixed rate context) likely avoids having the > interactions at issue. +1 I have skimmed the peripherial documentation for one of the Broadcom chips (I think the one from Raspberry Pi 3) and it says that the speed of the mini uart depends on the CPU clock frequency. I could imagine a situation when mini uart speed changes during downlocking the CPU. There was suggestion to not use mini uart. Use the port where the frequency is not changing with the weather. I don't know how smart is the power management with powerd, but I could also imagine shutting down peripherials or stopping the UART clock as a potential power saving feature, so here you are.