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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7A79CC43334 for ; Sat, 9 Jul 2022 20:41:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229459AbiGIUlZ (ORCPT ); Sat, 9 Jul 2022 16:41:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229448AbiGIUlY (ORCPT ); Sat, 9 Jul 2022 16:41:24 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1ED61DE92; Sat, 9 Jul 2022 13:41:24 -0700 (PDT) From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1657399282; 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=7XCPZYdFJvPl/+Lq/KH22t+YauCj8En8BB2tojor6b8=; b=HeLcSAxQmEJQcC6GvlmkZDTH5ZtG49b3ykeV2EIVRUeI2rxgNIyKXJKs9ryRVK7rXZmH88 wKwSW37aO9U+f6rLRLzBhwuMmyjG4xfQ81koAon7+3SscTt6TLu21zzU9CCEGtGzDnps44 2AtxdanRGr/145a5chmNqB4ThE6VXAUtKZYd00n1Q2bDHbXoVmeIaU6q3SHcc+IxqKZ4K5 +Dw7hjQjyNikDpbTrKqx8qoiK+qncNhRdj+UdzosVyE+6i1eA+mif4cuIR2nqQ/2isQu2e L94b7sxYxgmULo5UTSz4wob6xvkKWQBffqKWAxlXH41mTncZYDFX2j6gqXHFKQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1657399282; 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=7XCPZYdFJvPl/+Lq/KH22t+YauCj8En8BB2tojor6b8=; b=CDcPk9JxNXrHs6qzr3ETW9n1LgZiKi2wz+2s6K3eAe0PAiq/G1DNqmZcGJ089Wa6piWAla INv1+CdxaMjuJEDQ== To: todd.e.brandt@linux.intel.com, pmladek@suse.com Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, senozhatsky@chromium.org, rostedt@goodmis.org Subject: Re: PNP0501 serial driver takes almost 2 seconds to suspend/resume (printk issue) In-Reply-To: <045ebee30af2b80aaeace1dab18ecd113e3f17c7.camel@linux.intel.com> References: <12fb98fe27e23e3f74a139e5e8eb83a97a343372.camel@linux.intel.com> <51b9e2cc3baf61a604bd239b736ec2d12f1f6695.camel@linux.intel.com> <87czegxccb.fsf@jogness.linutronix.de> <045ebee30af2b80aaeace1dab18ecd113e3f17c7.camel@linux.intel.com> Date: Sat, 09 Jul 2022 22:47:21 +0206 Message-ID: <87tu7qvx1q.fsf@jogness.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org On 2022-07-08, Todd Brandt wrote: > The dmesg logs are in the html timelines themselves, just click the > "dmesg" button in the upper right hand corner. The log button shows > all kinds of system info as well. Since the beginning of the kernel log is missing, I still do not see information about which serial driver you are using. But since it is x86, I'll assume it is an 8250. Looking at freeze-5.19.0-rc1-bad.html, at 3431.221039 we see that suspend_console() was called. The additional 1-second delay you are referring to would be 3432.436187, where serial is suspended. pr_flush() would have been satisfied when the message at 3431.221039 was printed. So the question is, why is there still printing going on? @Todd: I assume you actually see all the messages up to and including 3431.506391 when it suspends? But the next message does not appear on suspend? I wonder if the console_lock()/console_unlock() within __pr_flush() is allowing extra printing to occur, for example if another CPU was calling printk. @Todd: Could you build your kernel with CONFIG_PRINTK_CALLER enabled? Also, please provide the last line you _see_ after a suspend. And finally, please make sure you are using the latest 5.19-rc. Thanks! John Ogness