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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 371BCC432C3 for ; Tue, 3 Dec 2019 13:27:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 02C7E2073B for ; Tue, 3 Dec 2019 13:27:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="C+pXhVT8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726131AbfLCN1k (ORCPT ); Tue, 3 Dec 2019 08:27:40 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:35120 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726086AbfLCN1j (ORCPT ); Tue, 3 Dec 2019 08:27:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding: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=eJyah7dYBX5u0LYEhSimzhwPDy/5Lpv50W9F2mk/SS4=; b=C+pXhVT8PUGcoJlnv3HYAff5f1 XowwDMrr+z2qLllhbeyjUcC1hA4hHNgGKyq0KZUdTFOQDQDiZkuo1lj6O3TKlOZf2ZHgc/RQSavrD XoKAFQdLGBgy0HdviZKTkFfklGO2nhRZbWYvhXaFACF507hffcHzonPwVehoDiDaSPdg=; Received: from andrew by vps0.lunn.ch with local (Exim 4.92.2) (envelope-from ) id 1ic8DC-0005YA-Qg; Tue, 03 Dec 2019 14:27:30 +0100 Date: Tue, 3 Dec 2019 14:27:30 +0100 From: Andrew Lunn To: Sam Lewis Cc: Steve Glendinning , UNGLinuxDriver@microchip.com, netdev@vger.kernel.org Subject: Re: PROBLEM: smsc95xx loses config on link down/up Message-ID: <20191203132730.GC1234@lunn.ch> References: <20191202134606.GA1234@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org > Basically it looks as though doing a BMCR_RESET does, in fact, reset > every PHY R/W register bit except for those marked as "Not Affected by > Software Reset" (NASR). This means it will reset, to the default > value: > > - Autonegotiation > - Speed > - Duplex > - Auto MDIX > - Energy Detect Power-Down > - Auto Negotiation Advertisement > - PHY Identification (although I don't know why you'd change this?) > - Power down > - Loopback > > I tested this by checking the value of the BMCR register before and > after doing a BMCR_RESET and it did reset the BMCR register to its > default values. O.K, not what we want. So there are two different paths here you can follow: 1) Moving the reset out of open and into bind. 2) Re-write the driver to make use of the core phylib support. 1) is probably the quick and simple solution, but watch out for suspend/resume. 2) is more work, but brings the driver into line with other MAC drivers. phylib would then program the PHY, maybe via PHY driver. It would do this during open, using state information. So it should correctly handle state change while the interface is down, or suspended etc. The USB-ethernet drivers lan78xx and ax88172a both use phylib. They can give you ideas how this should work. drivers/net/phy/smsc.c might be a good basis for a PHY driver, but it looks like you will need to extend it for MDIX, etc. Andrew