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 2BB01C77B7C for ; Thu, 3 Jul 2025 12:55:54 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=k1HNNILPSDl3Q34aXfxs4ZPYaPnX+sUSt9EkyNlpzwo=; b=JKp7kGMOu2IDzv5Olpchvt3b0E n7Dh8XTTWnhPAs4DwOWvxXKJBsH9lcwFAjbESt7Dgp1/9xQ62kAmxVv5kRv70zaiBBJr4nRB6LyXc s8C1KYSEzyVQvxtU8/rsTycALzf8cPcIBV/Pz8wbGAZafnTGZthDk1x6Ywrrz41aHoU16D+UMN8vd zfQyX3A74m+6yGQ6muWJqoU2SreJt5vsimSZqEKiyYlYm520+jDKRPpPGiov/QlsX7fVpqtMrJ92+ /g5sVFgRdFbP5bC9ufjWd2ke7kfGg9O4y+2JX9BPFWm7bOmJLLrZgXFDJz2Am71N9wmgjxD6N0qtN dTtgFqvg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uXJTg-0000000BPAM-00jM; Thu, 03 Jul 2025 12:55:48 +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 1uXIO9-0000000BCg6-2nFo for linux-arm-kernel@lists.infradead.org; Thu, 03 Jul 2025 11:46:04 +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 AD9DF1596; Thu, 3 Jul 2025 04:45:45 -0700 (PDT) Received: from localhost (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B5B1E3F6A8; Thu, 3 Jul 2025 04:45:59 -0700 (PDT) Date: Thu, 3 Jul 2025 12:45:57 +0100 From: Leo Yan To: Breno Leitao Cc: cov@codeaurora.org, rmk+kernel@armlinux.org.uk, mark.rutland@arm.com, catalin.marinas@arm.com, linux-serial@vger.kernel.org, rmikey@meta.com, linux-arm-kernel@lists.infradead.org, usamaarif642@gmail.com, linux-kernel@vger.kernel.org, paulmck@kernel.org Subject: Re: arm64: csdlock at early boot due to slow serial (?) Message-ID: <20250703114557.GD1039028@e132581.arm.com> References: <20250702172036.GC1039028@e132581.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250703_044601_748629_8AB530F0 X-CRM114-Status: GOOD ( 14.26 ) 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 Thu, Jul 03, 2025 at 03:02:39AM -0700, Breno Leitao wrote: [...] > > In some cases, if normal world and secure world share the same UART > > port, it can cause the UART state machine malfunction and long wait. > > I don't know how to check it for sure, but, looking at the serial > console output, I don't see anything else using the UART. The only > output I see on the console at that time is coming from linux kernel. > > Would you recommend any additional check? I have no experience in the driver, I should avoid any noise. But two things in my head for quick trying. - First, you could try earlycon mode, e.g., add option in kernel command line: earlycon=pl011,mmio32,0xc280000 earlycon=pl011,0xc280000 This would be possible to give more printing logs. If earlycon works well, then the issue might be caused by later init code (clock, or UART driver itself). - Try another UART port if this is possible. Just curious, you mentioned you are working on the mainline kernel. If you can confirm a workable kernel version, then this info can help to rule out hardware issue and we can review the delta changes. Thanks, Leo