From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 337A02DCF77 for ; Mon, 27 Oct 2025 07:25:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761549957; cv=none; b=tr9NbOULtsXeDfzuJKGmsDmeHU/9I2yawca1GYslXKgPE01e5FzEa64luyYD8zKGLcFxJ4G6aXG6MWEvx1pHwjCqBHTPeGm/gIDNcUgSM59ltM1/Y9Ln961GZ1HQdqCfOACLnkWjaXrp7VsRBy6gzu/aT72SUjK65/igPT1/Rvw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761549957; c=relaxed/simple; bh=i5JkEQeh/PyshRNknfWog6loFTBm7EwXHfGOtiMJB8A=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=Mdc0FQjup45fYPtEj4aVQIBv0SQj/TstO2ApJCvX2w1t0aGN9N0X8Nr/oIKYWGyRfMVhWJ7f6nKQZNAbhf2mEpldJLPgHcjlwt+cF2SqIJV4gp4Guc6/GLK8ZvSGEEBBWcDDsZqNHJqOgc6NTEiwkKBfpVizZjQImBkx8to+HBk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=S/j16NL5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="S/j16NL5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51561C4CEF1; Mon, 27 Oct 2025 07:25:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761549956; bh=i5JkEQeh/PyshRNknfWog6loFTBm7EwXHfGOtiMJB8A=; h=Subject:To:Cc:From:Date:From; b=S/j16NL5vU/9JVZ1T9Wp1+vWkvCZdClgL3iyQZIAzessR+OX3sV5ujWOfB+QpLckH lkaRBpfk8SX8G+l9QKH68JJU7DNOm7YeI7J0CRPIyjPWDk4LERQyc+GKC1/tBwPuKn /SVpMzcwozXRCmGXt0jnVWaCehNoCxawx+3mLN6I= Subject: FAILED: patch "[PATCH] serial: sc16is7xx: remove useless enable of enhanced features" failed to apply to 5.4-stable tree To: hvilleneuve@dimonoff.com,gregkh@linuxfoundation.org,stable@kernel.org Cc: From: Date: Mon, 27 Oct 2025 08:25:40 +0100 Message-ID: <2025102740-dumpster-clapper-519c@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 1c05bf6c0262f946571a37678250193e46b1ff0f # git commit -s git send-email --to '' --in-reply-to '2025102740-dumpster-clapper-519c@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 1c05bf6c0262f946571a37678250193e46b1ff0f Mon Sep 17 00:00:00 2001 From: Hugo Villeneuve Date: Mon, 6 Oct 2025 10:20:02 -0400 Subject: [PATCH] serial: sc16is7xx: remove useless enable of enhanced features Commit 43c51bb573aa ("sc16is7xx: make sure device is in suspend once probed") permanently enabled access to the enhanced features in sc16is7xx_probe(), and it is never disabled after that. Therefore, remove re-enable of enhanced features in sc16is7xx_set_baud(). This eliminates a potential useless read + write cycle each time the baud rate is reconfigured. Fixes: 43c51bb573aa ("sc16is7xx: make sure device is in suspend once probed") Cc: stable Signed-off-by: Hugo Villeneuve Link: https://patch.msgid.link/20251006142002.177475-1-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 1a2c4c14f6aa..c7435595dce1 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -588,13 +588,6 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) div /= prescaler; } - /* Enable enhanced features */ - sc16is7xx_efr_lock(port); - sc16is7xx_port_update(port, SC16IS7XX_EFR_REG, - SC16IS7XX_EFR_ENABLE_BIT, - SC16IS7XX_EFR_ENABLE_BIT); - sc16is7xx_efr_unlock(port); - /* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, SC16IS7XX_MCR_CLKSEL_BIT,