From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3B8082D8763; Fri, 5 Dec 2025 12:14:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764936856; cv=none; b=mc3eCIcDC1DbcoszIvYyVMJO/0jtOM3Uiv3KMEX8XeHPC2vgrzVlays+GidNASe4Fg1bIIor52IQTwkyeEPCPBpzcfp0a42/nDBNlZyc1Eqq9yU4DvpO8Q5Z1PYKgNULv47KGKYSdcjXDPh97KJrPc98mIGxtbYBr2Ki6ZCvEtA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764936856; c=relaxed/simple; bh=tb9j+MukMaeGM/TPRkOUt9KMW4y2sripMM5/CzKQ7+w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ehBiDNMAnZkKrL9G9qNxCqyr/lRjIgDqWYFzKjGPXiZmLPGQ0ZEwrhZyZHQHUFUkb1QQ6reLekWzY6znTPVXFm9Xu1/Qk5SKNmgG3DY5sGBpPJzOzaWKpMDT+ghnZBUEzZAK//yiKdlNa2EOC4ShD0slMziq3yjSNqb2s3eGq28= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com; spf=none smtp.mailfrom=foss.arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=foss.arm.com 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 7FBBC339; Fri, 5 Dec 2025 04:14:04 -0800 (PST) Received: from bogus (e133711.arm.com [10.1.196.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A816F3F86F; Fri, 5 Dec 2025 04:14:10 -0800 (PST) Date: Fri, 5 Dec 2025 12:14:07 +0000 From: Sudeep Holla To: Artem Shimko Cc: cristian.marussi@arm.com, arm-scmi@vger.kernel.org, Sudeep Holla , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4] firmware: arm_scmi: refactor reset domain handling Message-ID: <20251205-calculating-unique-ibex-de824e@sudeepholla> References: <20251123163557.230530-1-a.shimko.dev@gmail.com> <20251204-slick-granite-chameleon-58ebc2@sudeepholla> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Dec 05, 2025 at 01:36:23PM +0300, Artem Shimko wrote: > On Thu, Dec 4, 2025 at 7:26 PM Sudeep Holla wrote: > > > > On Sun, Nov 23, 2025 at 07:35:57PM +0300, Artem Shimko wrote: > > > Improve the SCMI reset protocol implementation by centralizing domain > > > validation and enhancing error handling. > > > > > > Add scmi_reset_domain_lookup() helper function to validate > > > domain ids and return appropriate error codes. Refactor all > > > domain-specific functions to use this helper, ensuring consistent > > > error handling throughout the reset protocol. > > > > > > Suggested-by: Cristian Marussi > > > Signed-off-by: Artem Shimko > > > --- > > > > > > Hi Cristian, > > > > > > Thank you for suggesting! If it works for you I'll try to improve the others protocols. > > > > > > It was tested on my board in QEMU and on real hardware. > > > The functionality didn't break, and peripherals that are reseted via SCMI work correctly. > > > > > > As an example, I can provide DMA test results (as one of the processor units dependent on SCMI reset). > > > > > > [ 2.559040] dw_axi_dmac_platform 1000nda0.nda_dma_0: DesignWare AXI DMA Controller, nda channels > > > [ 2.569265] dw_axi_dmac_platform 1000nda0.nda_dma_1: DesignWare AXI DMA Controller, nda channels > > > [ 2.580601] dw_axi_dmac_platform 1000nda0.nda_dma_2: DesignWare AXI DMA Controller, nda channels > > > > > > # echo 2000 > /sys/module/dmatest/parameters/timeout > > > # echo 1000 > /sys/module/dmatest/parameters/iterations > > > # echo dma0chan0 > /sys/module/dmatest/parameters/channel > > > [ 95.917504] dmatest: Added 1 threads using dma0chan0 > > > # echo 1 > /sys/module/dmatest/parameters/run > > > [ 101.931372] dmatest: Started 1 threads using dma0chan0 > > > [ 102.731009] dmatest: dma0chan0-copy0: summary 1000 tests, 0 failures 2508.42 iops 19706 KB/s (0) > > > > > > And vice versa: > > > > > > 1. Confirmed that the DMA module is non-functional without a proper reset via SCMI. > > > Disabling the reset logic causes a system crash on first access to its registers. > > > > > > 2. Requesting a non-existent reset domain: > > > > > > [ 2.463400] dw_axi_dmac_platform 1000nda0.nda_dma_0: error -EINVAL: Failed to deassert resets > > > [ 2.472091] dw_axi_dmac_platform 1000nda0.nda_dma_0: probe with driver dw_axi_dmac_platform failed with error -22 > > > [ 2.482911] dw_axi_dmac_platform 1000nda0.nda_dma_1: error -EINVAL: Failed to deassert resets > > > [ 2.491553] dw_axi_dmac_platform 1000nda0.nda_dma_1: probe with driver dw_axi_dmac_platform failed with error -22 > > > [ 2.502256] dw_axi_dmac_platform 1000nda0.nda_dma_2: error -EINVAL: Failed to deassert resets > > > [ 2.510735] dw_axi_dmac_platform 1000nda0.nda_dma_2: probe with driver dw_axi_dmac_platform failed with error -22 > > > > > > -- > > > Regards, > > > Artem > > > > > > --- > > > ChangeLog: > > > v4: Add Suggested-by tag > > > > > > drivers/firmware/arm_scmi/reset.c | 59 ++++++++++++++++++++----------- > > > 1 file changed, 39 insertions(+), 20 deletions(-) > > > > > > diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c > > > index 0aa82b96f41b..9854a3016d13 100644 > > > --- a/drivers/firmware/arm_scmi/reset.c > > > +++ b/drivers/firmware/arm_scmi/reset.c > > > @@ -100,6 +100,7 @@ static int scmi_reset_attributes_get(const struct scmi_protocol_handle *ph, > > > > > > static int > > > scmi_reset_domain_attributes_get(const struct scmi_protocol_handle *ph, > > > + struct reset_dom_info *dom_info, > > > > Instead of changing this, ... > > > > > struct scmi_reset_info *pinfo, > > > u32 domain, u32 version) > > > { > > > @@ -107,7 +108,6 @@ scmi_reset_domain_attributes_get(const struct scmi_protocol_handle *ph, > > > u32 attributes; > > > struct scmi_xfer *t; > > > struct scmi_msg_resp_reset_domain_attributes *attr; > > > - struct reset_dom_info *dom_info = pinfo->dom_info + domain; > > > > > > > ... You can just follow the pattern you have done everywhere else in this > > change like: > > > > struct reset_dom_info *dom_info; > > > > dom_info = scmi_reset_domain_lookup(ph, domain); > > if (IS_ERR(dom_info)) > > return PTR_ERR(dom_info); > > > > Any particular reason for not doing that ? > > Hi Sudeep, > > Based on perf.c, I added this pattern only to functions that can be > called externally with an invalid domain value. > Therefore, I decided it would be better to change the signature of > scmi_reset_domain_attributes_get (similar to > scmi_perf_domain_attributes_get from pref.c) > to ensure consistency across drivers when working with domain numbers. > > If you believe this pattern should be used in > scmi_reset_domain_attributes_get, I'll send you the next version of > the patch. > No need to post yet, I fixed it up here[1], let's see if Cristian agrees with that. Let me know if you are happy too with that change. I will rebase at -rc1 and apply it officially then. -- Regards, Sudeep [1] https://git.kernel.org/sudeep.holla/c/8bc55f21a345