From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [PATCH net-next 02/10] bnx2x: Removing indirect register access Date: Thu, 26 Jan 2012 21:50:08 +0000 Message-ID: <1327614608.2482.12.camel@bwh-desktop> References: <1327593714-18358-1-git-send-email-ariele@broadcom.com> <1327593714-18358-3-git-send-email-ariele@broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: , , , linux-pci To: Ariel Elior Return-path: Received: from mail.solarflare.com ([216.237.3.220]:23048 "EHLO ocex02.SolarFlarecom.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752735Ab2AZVuM (ORCPT ); Thu, 26 Jan 2012 16:50:12 -0500 In-Reply-To: <1327593714-18358-3-git-send-email-ariele@broadcom.com> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 2012-01-26 at 18:01 +0200, Ariel Elior wrote: > In virtualized environments indirect access to the device may not be supported > (depending on the Hypervisor type). Indirect device access was used since in > some harware contexts (i.e. certain chipset and BIOS) every access the driver > makes across the pci is followed by a BIOS initiated Zero Length Read to the > same address. [...] This is intriguing. Isn't that a general problem that can affect many devices? Can you be more specific about which systems have this behaviour? Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.