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[2620:137:e000::1:20]) by mx.google.com with ESMTP id h4-20020a633844000000b0052c8d7a08a4si1501807pgn.8.2023.06.01.13.20.24; Thu, 01 Jun 2023 13:20:38 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=fail header.i=@hugovil.com header.s=x header.b=FYMQTKBj; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232084AbjFAUTV (ORCPT + 99 others); Thu, 1 Jun 2023 16:19:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48332 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231856AbjFAUTF (ORCPT ); Thu, 1 Jun 2023 16:19:05 -0400 Received: from mail.hugovil.com (mail.hugovil.com [162.243.120.170]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5C908189; Thu, 1 Jun 2023 13:19:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hugovil.com ; s=x; h=Subject:Content-Transfer-Encoding:MIME-Version:References: In-Reply-To:Message-Id:Date:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=fISA+M83zRFEgKAdJUAq2HgGHBk9L99uymCON8uLsVo=; b=FYMQTKBjoNVaDM9a+tAIAyrw1X mMUS0palNJwjZcR42ck977uBOFvJQDnK8jSByhkWjnwB3/LIiTWmoupP6Tv/D6PX+I6QeHlgurJDm Nq5qkKQd3KXYkmNnFhMYy8f35yiJk7ynfq1vLE8mGSVlb+GhU+3CJ/tMSmAjAjMtuUuQ=; Received: from modemcable168.174-80-70.mc.videotron.ca ([70.80.174.168]:39204 helo=pettiford.lan) by mail.hugovil.com with esmtpa (Exim 4.92) (envelope-from ) id 1q4ol8-000686-Qz; Thu, 01 Jun 2023 16:18:59 -0400 From: Hugo Villeneuve To: gregkh@linuxfoundation.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, jirislaby@kernel.org, jringle@gridpoint.com, tomasz.mon@camlingroup.com, l.perczak@camlintechnologies.com Cc: linux-serial@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, hugo@hugovil.com, linux-gpio@vger.kernel.org, Hugo Villeneuve , Lech Perczak Date: Thu, 1 Jun 2023 16:18:43 -0400 Message-Id: <20230601201844.3739926-9-hugo@hugovil.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230601201844.3739926-1-hugo@hugovil.com> References: <20230601201844.3739926-1-hugo@hugovil.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 70.80.174.168 X-SA-Exim-Mail-From: hugo@hugovil.com X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Spam-Level: X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_PASS,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 Subject: [PATCH v6 8/9] serial: sc16is7xx: add post reset delay X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.hugovil.com) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1767533013547480143?= X-GMAIL-MSGID: =?utf-8?q?1767533013547480143?= From: Hugo Villeneuve Make sure we wait at least 3us before initiating communication with the device after reset. Signed-off-by: Hugo Villeneuve Reviewed-by: Lech Perczak Tested-by: Lech Perczak --- drivers/tty/serial/sc16is7xx.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 388c1d490853..9b2d58023c55 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1521,6 +1521,12 @@ static int sc16is7xx_probe(struct device *dev, regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT, SC16IS7XX_IOCONTROL_SRESET_BIT); + /* + * After reset, the host must wait at least 3us before initializing a + * communication with the device. + */ + usleep_range(5, 10); + for (i = 0; i < devtype->nr_uart; ++i) { s->p[i].line = i; /* Initialize port data */