From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 21BD62BEC4A; Tue, 4 Nov 2025 08:28:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762244920; cv=none; b=s1eq0tsTm+ydQSrnUAZS/7lW5KsVGb2gpWETb17JG3EkBo4MHxX6VzvnMUcY4DH/7JhZgnKtwMQuvsKCr43wjyAWObGDPl3HJsX677PdpPHHbl8EfPMYB/jqF+NoIXUGqYpdxGuqsMVeRotD768UwI12t/XwQsu+awYB/DHPDMk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762244920; c=relaxed/simple; bh=KRgnztshsryrhUg3jdsgqyFuCbUMtBMYBmlbKr9IW+U=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=Dvj41mggBg0mB5aNLEGcuyAha2XApoZLq6li4ot+CmC3usLBkq7K64g1GWKt9T9SyLWxykan/0Qh89plB0+cvE93ZlHi2yNwcETSxYv4tknWgXNWpLs35/7GblN+Z5NUBMUMD2uT03OfX4nb1H6kVmRTr4ybujRw26/MuJdOSEA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=IKZmuY5x; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=eex7FxTa; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="IKZmuY5x"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="eex7FxTa" From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1762244917; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=KRgnztshsryrhUg3jdsgqyFuCbUMtBMYBmlbKr9IW+U=; b=IKZmuY5xEME0fUnU+ODBigfDbR+GDPF0wsKdSVh7NOi0bmWHRzMOE1+0gnFtaFQt7K91Rz E04TcsoIRqznH5cFa9OSmu3xy29RxdOC55tX2z1bSHMqtM8qHadmIWKAkhDtXbvuIe1tBU K4RbiKQjDYBb5Mw1NaCvQvWD2I7w8GsEe7XlKItzPPXsGtmTI48td9ACPTPdw1uBXMzREk W278jp0r3Zw0t+VfuaxbbPP9dZ/WDVrmrV4vRW1F9Q5u6Ck78mImmH2yLPBnhiQTQSLExJ ZeAvo11+JhYTJmBZHxgLXPglB25/mYc5dGndQrXI9Z3aU0oELQnh5TRyqrRh6w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1762244917; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=KRgnztshsryrhUg3jdsgqyFuCbUMtBMYBmlbKr9IW+U=; b=eex7FxTaHfR53OT+DalJPlNTNLYO8jGKZD67BZ8V9MMyZJtH0QV8Sb1L7hk0hnTx2mgWoJ rTfNJ2OPUF/kHqCA== To: Sherry Sun , "esben@geanix.com" , "pmladek@suse.com" , "senozhatsky@chromium.org" , "tglx@linutronix.de" , Greg KH , Jiri Slaby , Shawn Guo , Sascha Hauer , "ryotkkr98@gmail.com" , "kkartik@nvidia.com" , "fj6611ie@aa.jp.fujitsu.com" Cc: Linux Kernel Mailing List , linux-serial , "imx@lists.linux.dev" , Pengutronix Kernel Team , "linux-pm@vger.kernel.org" Subject: Re: [BUG] Suspend failure with nbcon + pm_debug_messages (Linux 6.18-rc4) In-Reply-To: References: Date: Tue, 04 Nov 2025 09:34:36 +0106 Message-ID: <87tszamcaz.fsf@jogness.linutronix.de> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Hi Sherry, On 2025-11-04, Sherry Sun wrote: > Since the latest i.MX UART switch to nbcon console with commit > 70acca67bdd3 ("serial: imx: Switch to nbcon console"), I'm > encountering a suspend issue on an i.MX8MP EVK board while testing > with Linux 6.18-rc4. > > The system fails to suspend when both nbcon is enabled and > `pm_debug_messages` is turned on. When `pm_debug_messages` is > disabled, suspend works normally. Additionally, if I revert the patch > that adds nbcon support for the i.MX UART, suspend also works fine > even with `pm_debug_messages` enabled. Thanks for reporting! I believe this is the same issue reported by NVIDIA [0] when we tried to switch the 8250 UART driver to nbcon. We have been working with NVIDIA recently to address the issue. There is a patch [1] we are currently testing that looks good so far. It is based on 6.17 but should work fine for 6.18-rc4 as well. Can you give it a spin? John Ogness [0] https://lore.kernel.org/lkml/80b020fc-c18a-4da4-b222-16da1cab2f4c@nvidia.com [1] https://github.com/Linutronix/linux/commit/ae173249d9028ef159fba040bdab260d80dda43f