From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-vk0-f48.google.com (mail-vk0-f48.google.com [209.85.213.48]) by dpdk.org (Postfix) with ESMTP id 3486D532C for ; Tue, 5 Jul 2016 12:02:42 +0200 (CEST) Received: by mail-vk0-f48.google.com with SMTP id c2so258286509vkg.1 for ; Tue, 05 Jul 2016 03:02:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=semihalf-com.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=15flQAGHZLCrK3YG0YmLkab1cbkqyiQbdytz1tjQV9w=; b=LqQ49TSQ8su809Qajy0uWwnZJRjbdh0pEq5TZFP/Ppq5ypdIbGs7XC4m+3h8uAdz7b TCVY6GD9UJTaCauhRkvLcv1R/fQNOIkcShKMGiwCOR2Kif7OqD8CX0bGffCN/DU6NQ69 2+VPJzX4pWLVBCche9lIXc09G3J7Ruaju4tuXQPbHvGgat63ZXdJ8SxtrU+ZnyRXK01t aaiR6ZnW7Ut2loAIPR01LZxCbK0bC0S9ckTmoF76Ve099Dw8dNyM+DeLEGab0YtVHb0L KyK7sW01Gq6cSI2g0ZQ2S8fG+L8jMKk9b0o0tomJw/TVO3AkTfgyVRDzouGY9fR1BqNp J2VQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=15flQAGHZLCrK3YG0YmLkab1cbkqyiQbdytz1tjQV9w=; b=gTWQbBsv7Ajh8bAomeWsa6gA3ozxDmBrqFzBdP+Z5Ftp/Qgz+2qlPjSdgrWvCMtvFy wBAxIKSJ15ZKzLiFjku4Y6oObu35V4l3iHCRRHWRrRK1dEkmea8LYyC8F0uVut7093Up rstwSgCMoTWZaJcnlK41A7fx4aQ/CWv+p0CEUd5wUot9QPMJjRBlnoch2XwLiYmqURxf 2ZpmtLh/inj0cYip+yZ4Pygh47ziiKL/d+bxE1VIescmFXfmsAQci6hpLsvQzywzxJuD EJc0O4w38+JTLqQ5Kzxd3X9ydFPKe5qZQsgB4iPOAyLT6kwa6d6ldrP/ruj7L2h16Tag ZTJw== X-Gm-Message-State: ALyK8tKSaiMpCrjJE5sIssyOovDgmdJ7bGUgYgQc6eXw9Xd1nKHkZBUd5sPjWR1cbLK/mkU8vv7ChiG9J8PocA== X-Received: by 10.176.4.66 with SMTP id 60mr7036596uav.124.1467712961649; Tue, 05 Jul 2016 03:02:41 -0700 (PDT) MIME-Version: 1.0 Received: by 10.159.36.54 with HTTP; Tue, 5 Jul 2016 03:02:41 -0700 (PDT) In-Reply-To: <20160704154303.GA23380@bricha3-MOBL3> References: <1466510763-19569-6-git-send-email-jan@semihalf.com> <1467299099-32498-1-git-send-email-jan@semihalf.com> <1467299099-32498-4-git-send-email-jan@semihalf.com> <20160704154303.GA23380@bricha3-MOBL3> From: =?UTF-8?Q?Jan_M=C4=99dala?= Date: Tue, 5 Jul 2016 12:02:41 +0200 Message-ID: To: Bruce Richardson Cc: dev@dpdk.org, ferruh.yigit@intel.com, Alexander Matushevsky , Jakub Palider Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] [PATCH v3 3/6] ena: disable readless communication regarding to HW revision X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Jul 2016 10:02:42 -0000 Bruce, Here's explanation of readless communication (on behalf of Alex): > "readless" refers to ability to read ENA registers without actually > issuing read request from host (x86). > Instead, host programs 2 registers on device that trigger DMA from device > to host and report register value. > However, this functionality is not going to be available in all type of > devices. The decision if this mode is supported or not , is taken from > revision_id in pci configuration space. Regards Jan 2016-07-04 17:43 GMT+02:00 Bruce Richardson : > On Thu, Jun 30, 2016 at 05:04:56PM +0200, Jan Medala wrote: > > Depending on HW revision readless communcation between host and device > > may be unavailable. > > In that case prevent PMD of seting up readless communication mechanism. > > > The idea of readless communication is a strange one. Can you provide a bit > more detail as to what "readless communication" refers to. > > /Bruce >