From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stanimir Varbanov Subject: [PATCH 2/4] dmaengine: qcom_bam_dma: clear BAM interrupt only if it is rised Date: Tue, 1 Dec 2015 11:14:57 +0200 Message-ID: <1448961299-15161-3-git-send-email-stanimir.varbanov@linaro.org> References: <1448961299-15161-1-git-send-email-stanimir.varbanov@linaro.org> Return-path: In-Reply-To: <1448961299-15161-1-git-send-email-stanimir.varbanov@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, dmaengine@vger.kernel.org, Vinod Koul Cc: Rob Herring , Rob Herring , Mark Rutland , Pawel Moll , Ian Campbell , Andy Gross , Archit Taneja , Stanimir Varbanov List-Id: linux-arm-msm@vger.kernel.org Currently we write BAM_IRQ_CLR register with zero even when no BAM_IRQ occured. This write has some bad side effects when the BAM instance is for the crypto engine. In case of crypto engine some of the BAM registers are xPU protected and they cannot be controlled by the driver. Signed-off-by: Stanimir Varbanov --- drivers/dma/qcom_bam_dma.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/drivers/dma/qcom_bam_dma.c b/drivers/dma/qcom_bam_dma.c index dc9da477eb69..0f06f3b7a72b 100644 --- a/drivers/dma/qcom_bam_dma.c +++ b/drivers/dma/qcom_bam_dma.c @@ -800,13 +800,17 @@ static irqreturn_t bam_dma_irq(int irq, void *data) if (srcs & P_IRQ) tasklet_schedule(&bdev->task); - if (srcs & BAM_IRQ) + if (srcs & BAM_IRQ) { clr_mask = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_STTS)); - /* don't allow reorder of the various accesses to the BAM registers */ - mb(); + /* + * don't allow reorder of the various accesses to the BAM + * registers + */ + mb(); - writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR)); + writel_relaxed(clr_mask, bam_addr(bdev, 0, BAM_IRQ_CLR)); + } return IRQ_HANDLED; } -- 1.7.9.5