From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755199AbcEQDt7 (ORCPT ); Mon, 16 May 2016 23:49:59 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:38261 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752774AbcEQDtK (ORCPT ); Mon, 16 May 2016 23:49:10 -0400 From: Jiada Wang To: , CC: , , , , , Subject: [PATCH 08/10] dma: imx-sdma: abort updating channel when it has been terminated Date: Tue, 17 May 2016 12:48:54 +0900 Message-ID: <1463456936-10634-9-git-send-email-jiada_wang@mentor.com> X-Mailer: git-send-email 2.4.5 In-Reply-To: <1463456936-10634-1-git-send-email-jiada_wang@mentor.com> References: <1463456936-10634-1-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 In case the corresponding channel has already been terminated, then instead of go on updating channel status, driver should abort from sdma_handle_channel_loop(), otherwise channel status will be updated incorrecly. This patch also adds lock to avoid race between terminate of channel, and updaing of channel status in sdma_handle_channel_loop(). Signed-off-by: Jiada Wang --- drivers/dma/imx-sdma.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index 0b23407..bc867e5 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -664,16 +664,25 @@ static void sdma_event_disable(struct sdma_channel *sdmac, unsigned int event) static void sdma_handle_channel_loop(struct sdma_channel *sdmac) { struct sdma_buffer_descriptor *bd; + unsigned long flags; /* * loop mode. Iterate over descriptors, re-setup them and * call callback function. */ while (1) { + spin_lock_irqsave(&sdmac->lock, flags); + if (!sdmac->enabled) { + spin_unlock_irqrestore(&sdmac->lock, flags); + break; + } + bd = &sdmac->bd[sdmac->buf_tail]; - if (bd->mode.status & BD_DONE) + if (bd->mode.status & BD_DONE) { + spin_unlock_irqrestore(&sdmac->lock, flags); break; + } if (bd->mode.status & BD_RROR) sdmac->status = DMA_ERROR; @@ -690,6 +699,7 @@ static void sdma_handle_channel_loop(struct sdma_channel *sdmac) bd->mode.count = sdmac->chn_count; } + spin_unlock_irqrestore(&sdmac->lock, flags); if (sdmac->desc.callback) sdmac->desc.callback(sdmac->desc.callback_param); } -- 2.4.5