From patchwork Wed Apr 21 09:54:47 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Hovold X-Patchwork-Id: 425688 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3583C43470 for ; Wed, 21 Apr 2021 09:55:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 874DE61451 for ; Wed, 21 Apr 2021 09:55:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238679AbhDUJ4K (ORCPT ); Wed, 21 Apr 2021 05:56:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:52306 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238564AbhDUJ4J (ORCPT ); Wed, 21 Apr 2021 05:56:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 100E46144E; Wed, 21 Apr 2021 09:55:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618998936; bh=nhn87CK4iJ6zTd1Da+AXyC2e1yQ842t5WMdzZhpMx58=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nXC1quQIu4wfT/xbPUu7Ld+vnlbrcxuc+y/c9XSH5P9ItoR0uWWuc1PBiRNVYb3ms 8QAmnr2JEhr6X4Stt7kRiJksavMY+foLiVwe95NtIPuvmQBydI2iNkHPbIE8q79/i7 uc+GqjTZKc5jM6Q5gil3xO0qd26pcUDieoRgISN0tZuo+PvnKlrzU8mmpbro75ccZe QnTGmBttchBoQMIBxSHK/R9mwLmv/m7gXTdOH7NpYAX7R0M0ckFlfeUFyQkKZ4fR88 dN9OAzBCLVaPPEXXxhBCQHcr8w4CZBZofuSjzieKyx1FluhPKitoFESmCd+DIlo1KP /jL2/75gDF3dQ== Received: from johan by xi.lan with local (Exim 4.93.0.4) (envelope-from ) id 1lZ9a7-0000oV-1V; Wed, 21 Apr 2021 11:55:39 +0200 From: Johan Hovold To: Greg Kroah-Hartman Cc: Jiri Slaby , linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , Russell King Subject: [PATCH 04/26] serial: amba-pl010: drop low-latency workaround Date: Wed, 21 Apr 2021 11:54:47 +0200 Message-Id: <20210421095509.3024-5-johan@kernel.org> X-Mailer: git-send-email 2.26.3 In-Reply-To: <20210421095509.3024-1-johan@kernel.org> References: <20210421095509.3024-1-johan@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Commit 2389b272168c ("[ARM] 4417/1: Serial: Fix AMBA drivers locking") worked around the infamous low_latency behaviour of tty_flip_buffer_push() by simply dropping and reacquiring the port lock in the interrupt handler. Since commit a9c3f68f3cd8 ("tty: Fix low_latency BUG"), tty_flip_buffer_push() always schedules a work item to push data to the line discipline and there's no need to keep any low_latency hacks around. Cc: Russell King Signed-off-by: Johan Hovold --- drivers/tty/serial/amba-pl010.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/tty/serial/amba-pl010.c b/drivers/tty/serial/amba-pl010.c index 3f96edfe569c..e744b953ca34 100644 --- a/drivers/tty/serial/amba-pl010.c +++ b/drivers/tty/serial/amba-pl010.c @@ -159,9 +159,7 @@ static void pl010_rx_chars(struct uart_amba_port *uap) ignore_char: status = readb(uap->port.membase + UART01x_FR); } - spin_unlock(&uap->port.lock); tty_flip_buffer_push(&uap->port.state->port); - spin_lock(&uap->port.lock); } static void pl010_tx_chars(struct uart_amba_port *uap)