Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757556Ab3FTJ53 (ORCPT ); Thu, 20 Jun 2013 05:57:29 -0400 Received: from mail-pd0-f179.google.com ([209.85.192.179]:44457 "EHLO mail-pd0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755028Ab3FTJ51 (ORCPT ); Thu, 20 Jun 2013 05:57:27 -0400 MIME-Version: 1.0 In-Reply-To: <4881796E12491D4BB15146FE0209CE643F5F2F56@DE02WEMBXB.internal.synopsys.com> References: <1371629537-8076-1-git-send-email-abrodkin@synopsys.com> <4881796E12491D4BB15146FE0209CE643F5F2F56@DE02WEMBXB.internal.synopsys.com> From: Florian Fainelli Date: Thu, 20 Jun 2013 10:56:46 +0100 X-Google-Sender-Auth: b75K3pXAUE0-mFx36JRcomTNAws Message-ID: Subject: Re: [PATCH v5] ethernet/arc/arc_emac - Add new driver To: Alexey Brodkin Cc: Andy Shevchenko , netdev , Francois Romieu , Joe Perches , Vineet Gupta , Mischa Jonker , Arnd Bergmann , Grant Likely , Rob Herring , Paul Gortmaker , "David S. Miller" , "linux-kernel@vger.kernel.org" , Devicetree Discuss Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1463 Lines: 42 2013/6/20 Alexey Brodkin : [snip] > > In general MDIO register gets polled by "libphy" once in a couple of > seconds, so delay of 25 milliseconds IMHO is fine. > >>> +int arc_mdio_probe(struct device_node *dev_node, struct arc_emac_priv *priv) >>> +{ >> >>> + snprintf(bus->id, MII_BUS_ID_SIZE, "%.8x", (unsigned int)priv->regs); >> >> Is bus->id exposed to user-space somehow? > > Well as a boot-up message from "libphy": > ==== > libphy: Synopsys MII Bus: probed > ==== Well not only as a boot-up message, this serves as unique identifer in the entire system for your MDIO bus. It is crucial that you have an unique MDIO bus identifier for at least the two following reasons: - the corresponding kobject/sysfs node that is going to be created also needs to be unique in the system - you may have multiple MDIO bus in the system (e.g: the one for your specific driver and the fixed MDIO bus) Since you are using Device Tree already, you may just turn this into: snprintf(bus->id, MII_BUS_ID_SIZE, "%s", pdev->name); assuming that your node is already properly labelleled (e.g: mdio@deadbeef) which would be exactly equivalent to what you are doing with priv->regs; -- Florian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/