From patchwork Fri Nov 7 18:05:18 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Jon Medhurst (Tixy)" X-Patchwork-Id: 5254871 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id C45429F387 for ; Fri, 7 Nov 2014 18:08:49 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 138D720123 for ; Fri, 7 Nov 2014 18:08:49 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3DB6D2012E for ; Fri, 7 Nov 2014 18:08:48 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Xmnvv-0004XQ-2A; Fri, 07 Nov 2014 18:06:51 +0000 Received: from smarthost01a.mail.zen.net.uk ([212.23.1.1]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Xmnvg-0004SJ-MY for linux-arm-kernel@lists.infradead.org; Fri, 07 Nov 2014 18:06:37 +0000 Received: from [82.69.122.217] (helo=plug1) by smarthost01a.mail.zen.net.uk with esmtpsa (TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1XmnvC-0000ZT-Me; Fri, 07 Nov 2014 18:06:06 +0000 Received: from linaro1 ([192.168.2.110] helo=linaro1.home) by plug1 with esmtp (Exim 4.80) (envelope-from ) id 1Xmnv9-0002Di-6p; Fri, 07 Nov 2014 18:06:03 +0000 Received: from tixy by linaro1.home with local (Exim 4.84) (envelope-from ) id 1Xmnv9-0007e0-4V; Fri, 07 Nov 2014 18:06:03 +0000 From: Jon Medhurst To: Vinod Koul , Dan Williams , dmaengine@vger.kernel.org Subject: [PATCH 2/2] dma: pl330: Limit MFIFO usage for memcpy to avoid exhausting entries Date: Fri, 7 Nov 2014 18:05:18 +0000 Message-Id: <1415383518-29327-3-git-send-email-tixy@linaro.org> X-Mailer: git-send-email 2.1.1 In-Reply-To: <1415383518-29327-1-git-send-email-tixy@linaro.org> References: <1415383518-29327-1-git-send-email-tixy@linaro.org> X-Originating-smarthost01a-IP: [82.69.122.217] X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141107_100636_897646_DBCDC196 X-CRM114-Status: UNSURE ( 8.52 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -0.7 (/) Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The MFIFO is shared by all channels so restrict each memcpy to it's fair share. This is being over cautious, but without a global view of DMA channel usage on a system it's not possible to come up with a more optimum safe limit. Signed-off-by: Jon Medhurst --- drivers/dma/pl330.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 8f869ec..849439a 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2336,7 +2336,7 @@ static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len) int burst_len; burst_len = pl330->pcfg.data_bus_width / 8; - burst_len *= pl330->pcfg.data_buf_dep; + burst_len *= pl330->pcfg.data_buf_dep / pl330->pcfg.num_chan; burst_len >>= desc->rqcfg.brst_size; /* src/dst_burst_len can't be more than 16 */