From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yoshihiro Shimoda Subject: Re: [RFC/PATCH v3] sh_eth: use RNC mode for packet reception Date: Wed, 4 Jun 2014 09:29:14 +0900 Message-ID: <538E685A.1000505@renesas.com> References: <1401794473-30050-1-git-send-email-ben.dooks@codethink.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-2022-JP" Content-Transfer-Encoding: 7bit Cc: , , , To: Ben Dooks , , Return-path: Received: from relmlor2.renesas.com ([210.160.252.172]:63483 "EHLO relmlie1.idc.renesas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751589AbaFDA3W (ORCPT ); Tue, 3 Jun 2014 20:29:22 -0400 In-Reply-To: <1401794473-30050-1-git-send-email-ben.dooks@codethink.co.uk> Sender: netdev-owner@vger.kernel.org List-ID: Hi Ben, (2014/06/03 20:21), Ben Dooks wrote: > The current behaviour of the sh_eth driver is not to use the RNC bit > for the receive ring. This means that every packet recieved is not only > generating an IRQ but it also stops the receive ring DMA as well until > the driver re-enables it after unloading the packet. > > This means that a number of the following errors are generated due to > the receive packet FIFO overflowing due to nowhere to put packets: > > net eth0: Receive FIFO Overflow > > Since feedback from Yoshihiro Shimoda shows that every supported LSI > for this driver should have the bit enabled it seems the best way is > to remove the RMCR default value from the per-system data and just > write it when initialising the RMCR value. This is discussed in > the message (http://www.spinics.net/lists/netdev/msg284912.html). > > I have tested the RMCR_RNC configuration with NFS root filesystem and > the driver has not failed yet. There are further test reports from > Sergei Shtylov and others for both the R8A7790 and R8A7791. > > There is also feedback fron Cao Minh Hiep[1] which reports the > same issue in (http://comments.gmane.org/gmane.linux.network/316285) > showing this fixes issues with losing UDP datagrams under iperf. > > Tested-by: Sergei Shtylyov > Signed-off-by: Ben Dooks Thank you very much for the patch. Acked-by: Yoshihiro Shimoda Best regards, Yoshihiro Shimoda