From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932340AbcEQDsW (ORCPT ); Mon, 16 May 2016 23:48:22 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:38175 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932118AbcEQDsM (ORCPT ); Mon, 16 May 2016 23:48:12 -0400 From: Jiada Wang To: , CC: , , , , , Subject: [PATCH 10/10] dma: imx-sdma: clear channel0 interrupt bit in irq routine Date: Tue, 17 May 2016 12:47:56 +0900 Message-ID: <1463456876-10580-11-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 When SDMA channel0 timeouts, even it's disabled in error path, but sometimes we still see its interrupt bit be asserted, which causes irq routine be triggered continuously because no one else clears this bit. This commit clears channel0 interrupt as well in irq routine, so that even channel0 timeouts, it won't cause irq storm, also adds lock to prevent irq routine to clear this bit when sdma_run_channel0() is busy checking it. Signed-off-by: Jiada Wang --- drivers/dma/imx-sdma.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index 8b20bf4..ca1c984 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -768,12 +768,16 @@ static void sdma_tasklet(unsigned long data) static irqreturn_t sdma_int_handler(int irq, void *dev_id) { struct sdma_engine *sdma = dev_id; - unsigned long stat; + unsigned long stat, flags; + + spin_lock_irqsave(&sdma->channel_0_lock, flags); stat = readl_relaxed(sdma->regs + SDMA_H_INTR); + writel_relaxed(stat, sdma->regs + SDMA_H_INTR); /* not interested in channel 0 interrupts */ stat &= ~1; - writel_relaxed(stat, sdma->regs + SDMA_H_INTR); + + spin_unlock_irqrestore(&sdma->channel_0_lock, flags); while (stat) { int channel = fls(stat) - 1; -- 2.4.5