From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933799AbcECBXO (ORCPT ); Mon, 2 May 2016 21:23:14 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60621 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932591AbcECAeF (ORCPT ); Mon, 2 May 2016 20:34:05 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Shevchenko , Vinod Koul Subject: [PATCH 4.5 029/200] dmaengine: hsu: correct residue calculation of active descriptor Date: Mon, 2 May 2016 17:10:28 -0700 Message-Id: <20160503000555.571289433@linuxfoundation.org> X-Mailer: git-send-email 2.8.2 In-Reply-To: <20160503000554.631204776@linuxfoundation.org> References: <20160503000554.631204776@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Shevchenko commit a197f3c7d48c0c1f45076ea47533a76ba9b1a959 upstream. The commit f0579c8ceaf1 ("dmaengine: hsu: speed up residue calculation") speeded up calculation of the queued descriptor but broke the initial residue value for active descriptor. In accordance with documentation the hardware descriptor is updated each time DMA transfered some bytes. It means we have to calculate a sum of lengths of non-submitted hardware descriptors and whatever current values in the hardware. Do this straightforward. Fixes: f0579c8ceaf1 ("dmaengine: hsu: speed up residue calculation") Signed-off-by: Andy Shevchenko Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/hsu/hsu.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/dma/hsu/hsu.c +++ b/drivers/dma/hsu/hsu.c @@ -254,10 +254,13 @@ static void hsu_dma_issue_pending(struct static size_t hsu_dma_active_desc_size(struct hsu_dma_chan *hsuc) { struct hsu_dma_desc *desc = hsuc->desc; - size_t bytes = desc->length; + size_t bytes = 0; int i; - i = desc->active % HSU_DMA_CHAN_NR_DESC; + for (i = desc->active; i < desc->nents; i++) + bytes += desc->sg[i].len; + + i = HSU_DMA_CHAN_NR_DESC - 1; do { bytes += hsu_chan_readl(hsuc, HSU_CH_DxTSR(i)); } while (--i >= 0);