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 6196DC83F25 for ; Mon, 21 Jul 2025 13:22:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=U/5yH86xsu//oeNJeut1I4traXhSlmHdb3iC2ghKsiA=; b=i1RqY+Gqndeb7aw9BauVckCymA TBH/m4dAF8YXNAZt73z7leA362Mw0oppabB3f744h4Cog5ygL3YSp0vYv/GSjz7yCwII+eESAlIWS O9PTVC6nvfKUyfIyNAXprOCXVVn2VfRLIlNuZDrt1W/TCEAE4j5RXsq9wLJzVX21lIQfSppHW1B7K +plhL99TUI3w2stHO65Ox4rGdZpEB6XdoEKwgjHGc3El9eEHuOiOtoBfQvKxx6snZSLtA9Nta9E/g 4VepC9sNvXhwM34FvoHias215lHdVF4XY0fCiCJIETKtl/3cGfX1lnyxo+tbSnFLvSGtvIMFU3zDN HXX9tE2Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1udqTV-0000000HNSN-2kGq; Mon, 21 Jul 2025 13:22:37 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1udosv-0000000H9RK-3tMC for linux-arm-kernel@lists.infradead.org; Mon, 21 Jul 2025 11:40:47 +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 6DD54153B; Mon, 21 Jul 2025 04:40:34 -0700 (PDT) Received: from [10.57.30.25] (unknown [10.57.30.25]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 265A13F6A8; Mon, 21 Jul 2025 04:40:39 -0700 (PDT) Message-ID: <607c03a2-267c-46e6-a7fa-e733c1970e60@arm.com> Date: Mon, 21 Jul 2025 12:40:38 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 04/10] coresight: Appropriately disable programming clocks Content-Language: en-GB To: Leo Yan Cc: Mike Leach , James Clark , Anshuman Khandual , Alexander Shishkin , Greg Kroah-Hartman , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20250627-arm_cs_fix_clock_v4-v4-0-0ce0009c38f8@arm.com> <20250627-arm_cs_fix_clock_v4-v4-4-0ce0009c38f8@arm.com> <5a5f1355-563d-498a-9dec-3479a257b3e6@arm.com> <20250721104834.GC3137075@e132581.arm.com> From: Suzuki K Poulose In-Reply-To: <20250721104834.GC3137075@e132581.arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250721_044046_018444_BFDBEE5A X-CRM114-Status: GOOD ( 13.45 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 21/07/2025 11:48, Leo Yan wrote: > On Mon, Jul 21, 2025 at 10:15:22AM +0100, Suzuki Kuruppassery Poulose wrote: > > [...] > >>> diff --git a/include/linux/coresight.h b/include/linux/coresight.h >>> index 4ac65c68bbf44b98db22c3dad2d83a224ce5278e..dd2b4cc7a2b70cf060a3207548fe80e3824c489f 100644 >>> --- a/include/linux/coresight.h >>> +++ b/include/linux/coresight.h >>> @@ -480,26 +480,16 @@ static inline bool is_coresight_device(void __iomem *base) >>> * Returns: >>> * >>> * clk - Clock is found and enabled >>> - * NULL - clock is not found >> >> This is still valid, right ? > > No. Since this patch uses devm_clk_get_enabled() to get a clock, if the > pclk is not found, it returns -ENOENT (see of_parse_clkspec()). > > Only the optional clock APIs (e.g., devm_clk_get_optional_enabled()) > return a NULL pointer instead of -ENOENT when the clock is not found. This will break ACPI based systems, as we may not have a "pclk" described for them. We should be able to tolerate "no pclk" Suzuki > > Thanks, > Leo