From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH] e1000: Work around 82571 completion timout on Pseries HW Date: Thu, 17 May 2007 08:31:36 +1000 Message-ID: <1179354696.32247.231.camel@localhost.localdomain> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: e1000-devel@lists.sourceforge.net, netdev@vger.kernel.org, Auke Kok , Jeff Garzik To: Wen Xiong Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: e1000-devel-bounces@lists.sourceforge.net Errors-To: e1000-devel-bounces@lists.sourceforge.net List-Id: netdev.vger.kernel.org On Wed, 2007-05-16 at 17:11 -0500, Wen Xiong wrote: > little history, on PCI-X adapters we did not time dma reads being > returned to the adapter. On PCIe unfortunately the spec says that > adapters need to time the dma reads the spec is not specific on the > range but the timers can range from worst case 50 usecs to 10 ms with > some adapters supporting upto 50ms. The PCIe spec has approved an ECR > to the PCIe 1.0a spec that will support the ability to disable the > timer. To work aroung the adapter doesn't support ECR. We need the > driver to disable the timer. You do get more than 10ms delay for DMA replies on pSeries ? Ouch... Ben. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/