From: John Ogness Subject: [PATCH 1/3] ARM: common: edma: clear completion interrupts on stop Date: Mon, 27 Apr 2015 13:52:15 +0200 Message-ID: <87wq0xaivk.fsf@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: linux-serial@vger.kernel.org, Sekhar Nori , Peter Ujfalusi , Greg Kroah-Hartman , Sebastian Andrzej Siewior List-Id: linux-serial@vger.kernel.org When stopping a DMA transfer with interrupts disabled it is possible that the DMA transfer completes before the events are cleared. In this case the completion interrupt will be pending, causing a completion callback after the transfer was stopped. By clearing the completion interrupt for the stopping channel it is ensured that no completion event will be generated after the stop. Signed-off-by: John Ogness --- arch/arm/common/edma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c index 5662a87..873dbfc 100644 --- a/arch/arm/common/edma.c +++ b/arch/arm/common/edma.c @@ -1350,6 +1350,9 @@ void edma_stop(unsigned channel) edma_shadow0_write_array(ctlr, SH_SECR, j, mask); edma_write_array(ctlr, EDMA_EMCR, j, mask); + /* clear possibly pending completion interrupt */ + edma_shadow0_write_array(ctlr, SH_ICR, j, mask); + pr_debug("EDMA: EER%d %08x\n", j, edma_shadow0_read_array(ctlr, SH_EER, j)); -- 1.7.10.4