From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B9986C4360F for ; Wed, 3 Apr 2019 11:14:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 942D120643 for ; Wed, 3 Apr 2019 11:14:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726183AbfDCLOL (ORCPT ); Wed, 3 Apr 2019 07:14:11 -0400 Received: from regular1.263xmail.com ([211.150.70.200]:41570 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725935AbfDCLOL (ORCPT ); Wed, 3 Apr 2019 07:14:11 -0400 X-Greylist: delayed 364 seconds by postgrey-1.27 at vger.kernel.org; Wed, 03 Apr 2019 07:14:03 EDT Received: from sugar.zhang?rock-chips.com (unknown [192.168.167.131]) by regular1.263xmail.com (Postfix) with ESMTP id E0991340; Wed, 3 Apr 2019 19:07:49 +0800 (CST) X-263anti-spam: KSV:0;BIG:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ADDR-CHECKED4: 1 X-ABS-CHECKED: 1 X-SKE-CHECKED: 1 X-ANTISPAM-LEVEL: 2 Received: from localhost.localdomain (unknown [58.22.7.114]) by smtp.263.net (postfix) whith ESMTP id P28126T140503458764544S1554289667356895_; Wed, 03 Apr 2019 19:07:48 +0800 (CST) X-IP-DOMAINF: 1 X-UNIQUE-TAG: <6d284068b4b942efcdd023b0604119b3> X-RL-SENDER: sugar.zhang@rock-chips.com X-SENDER: zxg@rock-chips.com X-LOGIN-NAME: sugar.zhang@rock-chips.com X-FST-TO: heiko@sntech.de X-SENDER-IP: 58.22.7.114 X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 From: Sugar Zhang To: heiko@sntech.de, broonie@kernel.org Cc: linux-rockchip@lists.infradead.org, Sugar Zhang , Vinod Koul , Dan Williams , dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] dmaengine: pl330: _stop: clear interrupt status Date: Wed, 3 Apr 2019 19:06:22 +0800 Message-Id: <1554289582-43695-1-git-send-email-sugar.zhang@rock-chips.com> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch kill instructs the DMAC to immediately terminate execution of a thread. and then clear the interrupt status, at last, stop generating interrupts for DMA_SEV. to guarantee the next dma start is clean. otherwise, one interrupt maybe leave to next start and make some mistake. we can reporduce the problem as follows: DMASEV: modify the event-interrupt resource, and if the INTEN sets function as interrupt, the DMAC will set irq HIGH to generate interrupt. write INTCLR to clear interrupt. DMA EXECUTING INSTRUCTS DMA TERMINATE | | | | ... _stop | | | spin_lock_irqsave DMASEV | | | | mask INTEN | | | DMAKILL | | | spin_unlock_irqrestore in above case, a interrupt was left, and if we unmask INTEN, the DMAC will set irq HIGH to generate interrupt. to fix this, do as follows: DMA EXECUTING INSTRUCTS DMA TERMINATE | | | | ... _stop | | | spin_lock_irqsave DMASEV | | | | DMAKILL | | | clear INTCLR | mask INTEN | | | spin_unlock_irqrestore Signed-off-by: Sugar Zhang --- drivers/dma/pl330.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index eec79fd..56695ff 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -966,6 +966,7 @@ static void _stop(struct pl330_thread *thrd) { void __iomem *regs = thrd->dmac->base; u8 insn[6] = {0, 0, 0, 0, 0, 0}; + u32 inten = readl(regs + INTEN); if (_state(thrd) == PL330_STATE_FAULT_COMPLETING) UNTIL(thrd, PL330_STATE_FAULTING | PL330_STATE_KILLING); @@ -978,10 +979,13 @@ static void _stop(struct pl330_thread *thrd) _emit_KILL(0, insn); - /* Stop generating interrupts for SEV */ - writel(readl(regs + INTEN) & ~(1 << thrd->ev), regs + INTEN); - _execute_DBGINSN(thrd, insn, is_manager(thrd)); + + /* clear the event */ + if (inten & (1 << thrd->ev)) + writel(1 << thrd->ev, regs + INTCLR); + /* Stop generating interrupts for SEV */ + writel(inten & ~(1 << thrd->ev), regs + INTEN); } /* Start doing req 'idx' of thread 'thrd' */ -- 2.7.4