From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] net/ps3: Fix gelic RX DMA restart Date: Thu, 14 Jul 2011 16:03:40 -0700 (PDT) Message-ID: <20110714.160340.670777033431904110.davem@davemloft.net> References: <4E1F242E.7070509@infradead.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, cbe-oss-dev@lists.ozlabs.org To: geoff@infradead.org Return-path: Received: from shards.monkeyblade.net ([198.137.202.13]:53247 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932437Ab1GNXGv (ORCPT ); Thu, 14 Jul 2011 19:06:51 -0400 In-Reply-To: <4E1F242E.7070509@infradead.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Geoff Levand Date: Thu, 14 Jul 2011 10:15:26 -0700 > Fix the condition where PS3 network RX hangs when no network > TX is occurring by calling gelic_card_enable_rxdmac() during > RX_DMA_CHAIN_END event processing. > > The gelic hardware automatically clears its RX_DMA_EN flag when > it detects an RX_DMA_CHAIN_END event. In its processing of > RX_DMA_CHAIN_END the gelic driver is required to set RX_DMA_EN > (with a call to gelic_card_enable_rxdmac()) to restart RX DMA > transfers. The existing gelic driver code does not set > RX_DMA_EN directly in its processing of the RX_DMA_CHAIN_END > event, but uses a flag variable card->rx_dma_restart_required > to schedule the setting of RX_DMA_EN until next inside the > interrupt handler. > > It seems this delayed setting of RX_DMA_EN causes the hang since > the next RX interrupt after the RX_DMA_CHAIN_END event where > RX_DMA_EN is scheduled to be set will not occur since RX_DMA_EN > was not set. In the case were network TX is occuring, RX_DMA_EN > is set in the next TX interrupt and RX processing continues. > > Signed-off-by: Geoff Levand Applied.