From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751471AbbBDGQJ (ORCPT ); Wed, 4 Feb 2015 01:16:09 -0500 Received: from mx0a-0016f401.pphosted.com ([67.231.148.174]:43457 "EHLO mx0a-0016f401.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751114AbbBDGQH (ORCPT ); Wed, 4 Feb 2015 01:16:07 -0500 From: Qiao Zhou To: , , , , CC: Qiao Zhou Subject: [PATCH] dma: mmp-pdma: fix irq handler overwrite physical chan issue Date: Wed, 4 Feb 2015 14:16:03 +0800 Message-ID: <1423030563-2090-1-git-send-email-zhouqiao@marvell.com> X-Mailer: git-send-email 1.7.0.4 MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.13.68,1.0.33,0.0.0000 definitions=2015-02-04_02:2015-02-03,2015-02-04,1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=4 spamscore=4 suspectscore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1402240000 definitions=main-1502040067 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some dma channels may be reserved for other purpose in other layer, like secure driver in EL2/EL3. PDMA driver can see the interrupt status, but it should not try to handle related interrupt, since it doesn't belong to PDMA driver in kernel. These interrupts should be handled by corresponding client/module.Otherwise, it will overwrite illegal memory and cause unexpected issues, since pdma driver only requests resources for pdma channels. In PDMA driver, the reserved channels are at the end of total 32 channels. If we find interrupt bit index is not smaller than total dma channels, we should ignore it. Signed-off-by: Qiao Zhou --- drivers/dma/mmp_pdma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index 8b8952f..68ab55f 100644 --- a/drivers/dma/mmp_pdma.c +++ b/drivers/dma/mmp_pdma.c @@ -219,6 +219,9 @@ static irqreturn_t mmp_pdma_int_handler(int irq, void *dev_id) while (dint) { i = __ffs(dint); + /* only handle interrupts belonging to pdma driver*/ + if (i >= pdev->dma_channels) + break; dint &= (dint - 1); phy = &pdev->phy[i]; ret = mmp_pdma_chan_handler(irq, phy); -- 1.7.9.5