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 X-Spam-Level: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 9142DC433E6 for ; Fri, 5 Feb 2021 22:56:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 368FB64DDD for ; Fri, 5 Feb 2021 22:56:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232622AbhBEW4D (ORCPT ); Fri, 5 Feb 2021 17:56:03 -0500 Received: from mail.kernel.org ([198.145.29.99]:43242 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232707AbhBEOld (ORCPT ); Fri, 5 Feb 2021 09:41:33 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id E8E7C64FCA; Fri, 5 Feb 2021 14:09:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612534154; bh=c7Q8ewKd/jRSRoeS+fbFYVXJ7RfUsOeiMX6bRQu4UYg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0XSZoagzfJjY+ItuMtSVaLkrqBCNjszBkDE/3N0IaO4hCFEElyfRjdkHkwZGFgwwQ VDGOBpoGsoJ4259D4GMH0sM8qlqxcIrw+YWq3oypKRSSI4rMObhD4o/R5iQ2BWDtQX 8dYZxPLDVIn7rPwBPh3AIhd5bq3nbJFJfgVHqqkA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Florian Fainelli , Marek Vasut , Michael Grzeschik , Paul Barker , Andrew Lunn , Jakub Kicinski Subject: [PATCH 5.10 01/57] net: dsa: microchip: Adjust reset release timing to match reference reset circuit Date: Fri, 5 Feb 2021 15:06:27 +0100 Message-Id: <20210205140656.043955711@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210205140655.982616732@linuxfoundation.org> References: <20210205140655.982616732@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Marek Vasut commit 1c45ba93d34cd6af75228f34d0675200c81738b5 upstream. KSZ8794CNX datasheet section 8.0 RESET CIRCUIT describes recommended circuit for interfacing with CPU/FPGA reset consisting of 10k pullup resistor and 10uF capacitor to ground. This circuit takes ~100 ms to rise enough to release the reset. For maximum supply voltage VDDIO=3.3V VIH=2.0V R=10kR C=10uF that is VDDIO - VIH t = R * C * -ln( ------------- ) = 10000*0.00001*-(-0.93)=0.093 s VDDIO so we need ~95 ms for the reset to really de-assert, and then the original 100us for the switch itself to come out of reset. Simply msleep() for 100 ms which fits the constraint with a bit of extra space. Fixes: 5b797980908a ("net: dsa: microchip: Implement recommended reset timing") Reviewed-by: Florian Fainelli Signed-off-by: Marek Vasut Cc: Michael Grzeschik Reviewed-by: Paul Barker Reviewed-by: Andrew Lunn Link: https://lore.kernel.org/r/20210120030502.617185-1-marex@denx.de Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/dsa/microchip/ksz_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index 489963664443..389abfd27770 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -400,7 +400,7 @@ int ksz_switch_register(struct ksz_device *dev, gpiod_set_value_cansleep(dev->reset_gpio, 1); usleep_range(10000, 12000); gpiod_set_value_cansleep(dev->reset_gpio, 0); - usleep_range(100, 1000); + msleep(100); } mutex_init(&dev->dev_mutex); -- 2.30.0