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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BFCBDC4332F for ; Thu, 3 Nov 2022 11:23:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=n77gJUoDjb/1M5wQ4ixFKFnf/JoBh/evNqBQAuh4XvY=; b=z/IkwvkYpqt4wT 7SqihkkXz8prPndMbNKp+3+oqwPFN6JyBPQUjGxt3K0tMTCjV05DNWLgbZzAd3DfCDpylJG4N5oPU FrOOvmwscYQkzqBLol6Pu+5gqilg/biKieER5tgiWakW0OpPQ1XjQevJy2+oOw3ZPi4GbQaYVSpMa 3KPf/2xqAujOtR8tdGbWTade/7xGO0ELhL6HJa47OgTNeXy/88Jo0kpU88OqWuxKlsU5YbNU0/MH3 fUajnuHUqPaFq0QycmFs5X8AX2JubHCqNepztByC34WaswUzBnf7RfgBVN/w2RPCUrUf1ILrP3f1O ejhiBXt9dpaazRi4tXLw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oqYIK-00HCH7-CQ; Thu, 03 Nov 2022 11:22:00 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oqYIG-00HCGG-SQ for linux-arm-kernel@lists.infradead.org; Thu, 03 Nov 2022 11:21:58 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 981A01FB; Thu, 3 Nov 2022 04:21:57 -0700 (PDT) Received: from bogus (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 716973F5A1; Thu, 3 Nov 2022 04:21:49 -0700 (PDT) Date: Thu, 3 Nov 2022 11:21:47 +0000 From: Sudeep Holla To: Florian Fainelli Cc: Cristian Marussi , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.quinlan@broadcom.com, Jonathan.Cameron@Huawei.com, etienne.carriere@linaro.org, vincent.guittot@linaro.org, souvik.chakravarty@arm.com, wleavitt@marvell.com, peter.hilber@opensynergy.com, nicola.mazzucato@arm.com, tarek.el-sherbiny@arm.com, quic_kshivnan@quicinc.com, Sudeep Holla Subject: Re: [PATCH v4 0/11] Introduce a unified API for SCMI Server testing Message-ID: <20221103112147.rq2v7dwte577kmb4@bogus> References: <20221019204626.3813043-1-cristian.marussi@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221103_042156_992070_5371AB67 X-CRM114-Status: GOOD ( 21.62 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Oct 28, 2022 at 07:38:25PM -0700, Florian Fainelli wrote: > Hi Christian, > > On 10/19/2022 1:46 PM, Cristian Marussi wrote: > [snip] > > > In V2 the runtime enable/disable switching capability has been removed > > (for now) since still not deemed to be stable/reliable enough: as a > > consequence when SCMI Raw support is compiled in, the regular SCMI stack > > drivers are now inhibited permanently for that Kernel. > > For our platforms (ARCH_BRCMSTB) we would need to have the ability to start > with the regular SCMI stack to satisfy if nothing else, all clock consumers > otherwise it makes it fairly challenging for us to boot to a prompt as we > purposely turn off all unnecessary peripherals to conserve power. We could > introduce a "full on" mode to remove the clock provider dependency, but I > suspect others on "real" silicon may suffer from the same short comings. > Fair enough. But if we are doing SCMI firmware testing or conformance via the $subject proposed way, can these drivers survive if the userspace do a random or a torture test changing the clock configurations ? Not sure how to deal with that as the intention here is to do the testing from the user-space and anything can happen. How do we avoid bring the entire system down while doing this testing. Can we unbind all the drivers using scmi on your platform ? I guess no. Let me know. > Once user-space is reached, I suppose we could find a way to unbind from all > SCMI consumers, and/or ensure that runtime PM is disabled, cpufreq is in a > governor that won't do any active frequency switching etc. > > What do you think? Yes, Cristian always wanted to support that but I am the one trying to convince him not to unless there is a strong requirement for it. You seem to suggest that you have such a requirement, but that just opens loads of questions and how to we deal with that. Few of them are as stated above, I need to recall all the conversations I had with Cristian around that and why handling it may be bit complex. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel