From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754615AbcEQDsA (ORCPT ); Mon, 16 May 2016 23:48:00 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:38127 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754036AbcEQDr5 (ORCPT ); Mon, 16 May 2016 23:47:57 -0400 From: Jiada Wang To: , CC: , , , , , Subject: [PATCH 01/10] dma: imx-sdma: use chn_real_count to report residue for UART Date: Tue, 17 May 2016 12:47:47 +0900 Message-ID: <1463456876-10580-2-git-send-email-jiada_wang@mentor.com> X-Mailer: git-send-email 2.4.5 In-Reply-To: <1463456876-10580-1-git-send-email-jiada_wang@mentor.com> References: <1463456876-10580-1-git-send-email-jiada_wang@mentor.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org For uart rx dma data may not receive fully, so the number of data read by sdma script once isn't always equal to period_len, thus residue returned from sdma_tx_status() isn't valid for uart rx dma. The old way to use chn_real_count to report residue should be used for uart rx dma. Signed-off-by: Jiada Wang --- drivers/dma/imx-sdma.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index 0f6fd42..1f1b64b 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -680,6 +680,11 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac) bd->mode.status |= BD_DONE; sdmac->buf_tail++; sdmac->buf_tail %= sdmac->num_bd; + if (sdmac->peripheral_type == IMX_DMATYPE_UART) { + /* restore mode.count after counter readed */ + sdmac->chn_real_count = bd->mode.count; + bd->mode.count = sdmac->chn_count; + } } } @@ -1285,6 +1290,9 @@ static struct dma_async_tx_descriptor *sdma_prep_dma_cyclic( goto err_out; } + if (sdmac->peripheral_type == IMX_DMATYPE_UART) + sdmac->chn_count = period_len; + while (buf < buf_len) { struct sdma_buffer_descriptor *bd = &sdmac->bd[i]; int param; @@ -1361,7 +1369,8 @@ static enum dma_status sdma_tx_status(struct dma_chan *chan, struct sdma_channel *sdmac = to_sdma_chan(chan); u32 residue; - if (sdmac->flags & IMX_DMA_SG_LOOP) + if ((sdmac->flags & IMX_DMA_SG_LOOP) && + (sdmac->peripheral_type != IMX_DMATYPE_UART)) residue = (sdmac->num_bd - sdmac->buf_tail) * sdmac->period_len; else residue = sdmac->chn_count - sdmac->chn_real_count; -- 2.4.5