From 54eb5e26cbb72ba77588098385bf5f492b8323ae Mon Sep 17 00:00:00 2001 From: Srinivas Kandagatla Date: Thu, 15 Feb 2018 12:25:10 +0000 Subject: [PATCH] dmaengine: qcom: bam_dma: do not write to global regs in remote mode BAM_DESC_CNT_TRSHLD register is global register, which can only be written when BAM is in master mode, So check the mode of operation before writing it. Without this check SOC's xPU would catch such access and crash the system. First noticed on DB820c while testing SLIMBus BAM. Signed-off-by: Srinivas Kandagatla Signed-off-by: Vinod Koul --- drivers/dma/qcom/bam_dma.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c index 139e9f5e47a9..6919f501b9f3 100644 --- a/drivers/dma/qcom/bam_dma.c +++ b/drivers/dma/qcom/bam_dma.c @@ -935,12 +935,15 @@ static void bam_apply_new_config(struct bam_chan *bchan, struct bam_device *bdev = bchan->bdev; u32 maxburst; - if (dir == DMA_DEV_TO_MEM) - maxburst = bchan->slave.src_maxburst; - else - maxburst = bchan->slave.dst_maxburst; + if (!bdev->controlled_remotely) { + if (dir == DMA_DEV_TO_MEM) + maxburst = bchan->slave.src_maxburst; + else + maxburst = bchan->slave.dst_maxburst; - writel_relaxed(maxburst, bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD)); + writel_relaxed(maxburst, + bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD)); + } bchan->reconfigure = 0; }