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 4A571EB64D8 for ; Sun, 18 Jun 2023 12:50:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229511AbjFRMuC (ORCPT ); Sun, 18 Jun 2023 08:50:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34826 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229509AbjFRMuA (ORCPT ); Sun, 18 Jun 2023 08:50:00 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11B3DE4D for ; Sun, 18 Jun 2023 05:50:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A244060ACE for ; Sun, 18 Jun 2023 12:49:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B4EEAC433C0; Sun, 18 Jun 2023 12:49:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687092599; bh=kXRvJtNRP1k67oHtgGifA8q1go/Dlr48dQKAYdJhfh4=; h=Subject:To:Cc:From:Date:From; b=0HsqYVy4Hj8Li9HiSYlLqtet/Ccf1GvnvViNqssUNFtTe+d1/N6TLg6KgIr0WFxgk deDkdmfBqise5z6c4SSYI/1pfO8UCL4kE459Vnd15BOiSe9AYDLG37ha2Ovh+WO+GF 4GD61h+muffuQInW7x6cOVJBr/y/EZYdQAzZzE9E= Subject: FAILED: patch "[PATCH] tty: serial: fsl_lpuart: reduce RX watermark to 0 on LS1028A" failed to apply to 5.15-stable tree To: robert.hodaszi@digi.com, gregkh@linuxfoundation.org, stable@kernel.org Cc: From: Date: Sun, 18 Jun 2023 14:49:48 +0200 Message-ID: <2023061848-unpleased-sizing-050f@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.15-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-5.15.y git checkout FETCH_HEAD git cherry-pick -x a82c3df955f8c1c726e4976527aa6ae924a67dd9 # git commit -s git send-email --to '' --in-reply-to '2023061848-unpleased-sizing-050f@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From a82c3df955f8c1c726e4976527aa6ae924a67dd9 Mon Sep 17 00:00:00 2001 From: Robert Hodaszi Date: Fri, 9 Jun 2023 14:13:34 +0200 Subject: [PATCH] tty: serial: fsl_lpuart: reduce RX watermark to 0 on LS1028A LS1028A is using DMA with LPUART. Having RX watermark set to 1, means DMA transactions are started only after receiving the second character. On other platforms with newer LPUART IP, Receiver Idle Empty function initiates the DMA request after the receiver is idling for 4 characters. But this feature is missing on LS1028A, which is causing a 1-character delay in the RX direction on this platform. Set RX watermark to 0 to initiate RX DMA after each character. Link: https://lore.kernel.org/linux-serial/20230607103459.1222426-1-robert.hodaszi@digi.com/ Fixes: 9ad9df844754 ("tty: serial: fsl_lpuart: Fix the wrong RXWATER setting for rx dma case") Cc: stable Signed-off-by: Robert Hodaszi Message-ID: <20230609121334.1878626-1-robert.hodaszi@digi.com> Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 7486a2b8556c..7fd30fcc10c6 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -310,7 +310,7 @@ static const struct lpuart_soc_data ls1021a_data = { static const struct lpuart_soc_data ls1028a_data = { .devtype = LS1028A_LPUART, .iotype = UPIO_MEM32, - .rx_watermark = 1, + .rx_watermark = 0, }; static struct lpuart_soc_data imx7ulp_data = {