From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934038AbcCHANy (ORCPT ); Mon, 7 Mar 2016 19:13:54 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:44903 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933948AbcCHAEQ (ORCPT ); Mon, 7 Mar 2016 19:04:16 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vasily Khoruzhick , Robert Jarzmik , Vinod Koul Subject: [PATCH 4.4 43/74] dmaengine: pxa_dma: fix cyclic transfers Date: Mon, 7 Mar 2016 16:03:08 -0800 Message-Id: <20160308000316.668136748@linuxfoundation.org> X-Mailer: git-send-email 2.7.2 In-Reply-To: <20160308000315.294406921@linuxfoundation.org> References: <20160308000315.294406921@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 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Robert Jarzmik commit f16921275cc3c2442d0b95225785a601603b990f upstream. While testing audio with pxa2xx-ac97, underrun were happening while the user application was correctly feeding the music. Debug proved that the cyclic transfer is not cyclic, ie. the last descriptor did not loop on the first. Another issue is that the descriptor length was always set to 8192, because of an trivial operator issue. This was tested on a pxa27x platform. Fixes: a57e16cf0333 ("dmaengine: pxa: add pxa dmaengine driver") Reported-by: Vasily Khoruzhick Tested-by: Vasily Khoruzhick Signed-off-by: Robert Jarzmik Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- drivers/dma/pxa_dma.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/dma/pxa_dma.c +++ b/drivers/dma/pxa_dma.c @@ -583,6 +583,8 @@ static void set_updater_desc(struct pxad (PXA_DCMD_LENGTH & sizeof(u32)); if (flags & DMA_PREP_INTERRUPT) updater->dcmd |= PXA_DCMD_ENDIRQEN; + if (sw_desc->cyclic) + sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr = sw_desc->first; } static bool is_desc_completed(struct virt_dma_desc *vd) @@ -673,6 +675,10 @@ static irqreturn_t pxad_chan_handler(int dev_dbg(&chan->vc.chan.dev->device, "%s(): checking txd %p[%x]: completed=%d\n", __func__, vd, vd->tx.cookie, is_desc_completed(vd)); + if (to_pxad_sw_desc(vd)->cyclic) { + vchan_cyclic_callback(vd); + break; + } if (is_desc_completed(vd)) { list_del(&vd->node); vchan_cookie_complete(vd); @@ -1080,7 +1086,7 @@ pxad_prep_dma_cyclic(struct dma_chan *dc return NULL; pxad_get_config(chan, dir, &dcmd, &dsadr, &dtadr); - dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH | period_len); + dcmd |= PXA_DCMD_ENDIRQEN | (PXA_DCMD_LENGTH & period_len); dev_dbg(&chan->vc.chan.dev->device, "%s(): buf_addr=0x%lx len=%zu period=%zu dir=%d flags=%lx\n", __func__, (unsigned long)buf_addr, len, period_len, dir, flags);