From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-bw0-f174.google.com ([209.85.218.174]:35000 "EHLO mail-bw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752771AbZERSxH (ORCPT ); Mon, 18 May 2009 14:53:07 -0400 Received: by bwz22 with SMTP id 22so3389228bwz.37 for ; Mon, 18 May 2009 11:53:07 -0700 (PDT) To: Max Filippov Cc: linux-wireless@vger.kernel.org, Christian Lamparter Subject: Re: [PATCH 5/5] p54spi: use firmware/DMA bug workaround that work under hight load in p54spi_rx References: <1242601355-3178-1-git-send-email-jcmvbkbc@gmail.com> <1242601355-3178-2-git-send-email-jcmvbkbc@gmail.com> <1242601355-3178-3-git-send-email-jcmvbkbc@gmail.com> <1242601355-3178-4-git-send-email-jcmvbkbc@gmail.com> <1242601355-3178-5-git-send-email-jcmvbkbc@gmail.com> <1242601355-3178-6-git-send-email-jcmvbkbc@gmail.com> From: Kalle Valo Date: Mon, 18 May 2009 21:53:05 +0300 In-Reply-To: <1242601355-3178-6-git-send-email-jcmvbkbc@gmail.com> (Max Filippov's message of "Mon\, 18 May 2009 03\:02\:35 +0400") Message-ID: <87tz3i9ram.fsf@litku.valot.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: Max Filippov writes: > Under high load first data word, read after available data size > is sometimes lost in p54spi_rx. It seems to depend on frequency > of interrupts and latency of data read request relatively to > 'data available' interrupt. The worst consequence of this bug > is loss of packet transmission acknowledgement, which in turn > causes overflow of tx queues and permanent link loss. > > Read data size and first data word in one SPI transaction. > No packets from LMAC should have length less than 1 word, > so this shouldn't interfere with the next read transaction. There is a bug in omap2_mcspi which corrupts some DMA transfers, I don't know if the bug you see is this one or something else. I'll send the patch to linux-omap sometime later this week. -- Kalle Valo