From patchwork Wed Mar 16 14:36:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wander Lairson Costa X-Patchwork-Id: 552128 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 0B58EC433EF for ; Wed, 16 Mar 2022 14:37:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344173AbiCPOjA (ORCPT ); Wed, 16 Mar 2022 10:39:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36610 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344898AbiCPOiy (ORCPT ); Wed, 16 Mar 2022 10:38:54 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2895B53B5B for ; Wed, 16 Mar 2022 07:37:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647441459; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cQKY17K5M4BrRuM2rlw2MvxoRzLJI6+f/LllmsWpF+I=; b=ZEEHqOiqj0e5s5Lqwffy04kDtS0d+SZOoHPPeKD5jYQYz2B1KweiEaVSesKqLhMUGMYS56 QMh3gH8a32cOF8QxuzylVh2vodr+UT+dRh62UYODs2fnQsvpCXYAfDt509I03/6VEtmUik T4caCi6ErLa2VkW7MvQOamSZzZLa6MM= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-631-5OMsHSpZOEiI2NivE8y1Rg-1; Wed, 16 Mar 2022 10:37:36 -0400 X-MC-Unique: 5OMsHSpZOEiI2NivE8y1Rg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 277351066558; Wed, 16 Mar 2022 14:37:35 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.22.19.38]) by smtp.corp.redhat.com (Postfix) with ESMTP id E6895400F73E; Wed, 16 Mar 2022 14:37:31 +0000 (UTC) From: Wander Lairson Costa To: Greg Kroah-Hartman , Jiri Slaby , Johan Hovold , Wander Lairson Costa , "Maciej W. Rozycki" , Serge Semin , Lukas Wunner , =?utf-8?q?Pali_Roh=C3=A1r?= , linux-serial@vger.kernel.org (open list:SERIAL DRIVERS), linux-kernel@vger.kernel.org (open list) Cc: rostedt@goodmis.org, senozhatsky@chromium.org, andre.goddard@gmail.com, sudipm.mukherjee@gmail.com, andy.shevchenko@gmail.com, David.Laight@aculab.com, jonathanh@nvidia.com, phil@raspberrypi.com Subject: [PATCH v4 2/5] serial/8250: Use the cache value of the FCR register Date: Wed, 16 Mar 2022 11:36:41 -0300 Message-Id: <20220316143646.13301-3-wander@redhat.com> In-Reply-To: <20220316143646.13301-1-wander@redhat.com> References: <20220316143646.13301-1-wander@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org commit 5021d709b31b ("tty: serial: Use fifo in 8250 console driver") erroneous tries to read the FCR register content, but this register is write-only. This patch fixes that by reading the content from the port struct fcr field. Thanks to Jon Hunter and Jiri Slaby. Suggested-by: Jiri Slaby Reported-by: Jon Hunter Signed-off-by: Wander Lairson Costa --- drivers/tty/serial/8250/8250_port.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 2abb3de11a48..9f3fa9fe2a4e 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -3410,7 +3410,7 @@ void serial8250_console_write(struct uart_8250_port *up, const char *s, use_fifo = (up->capabilities & UART_CAP_FIFO) && port->fifosize > 1 && - (serial_port_in(port, UART_FCR) & UART_FCR_ENABLE_FIFO) && + (up->fcr & UART_FCR_ENABLE_FIFO) && /* * After we put a data in the fifo, the controller will send * it regardless of the CTS state. Therefore, only use fifo