From 57a7138d0627309d469719f1845d2778c251f358 Mon Sep 17 00:00:00 2001 From: Md Sadre Alam Date: Fri, 20 Dec 2024 15:12:03 +0530 Subject: [PATCH] dmaengine: qcom: bam_dma: Avoid writing unavailable register Avoid writing unavailable register in BAM-Lite mode. BAM_DESC_CNT_TRSHLD register is unavailable in BAM-Lite mode. Its only available in BAM-NDP mode. So only write this register for clients who is using BAM-NDP. Signed-off-by: Md Sadre Alam Link: https://lore.kernel.org/r/20241220094203.3510335-1-quic_mdalam@quicinc.com Signed-off-by: Vinod Koul --- drivers/dma/qcom/bam_dma.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c index bbc3276992bb..c14557efd577 100644 --- a/drivers/dma/qcom/bam_dma.c +++ b/drivers/dma/qcom/bam_dma.c @@ -59,6 +59,9 @@ struct bam_desc_hw { #define DESC_FLAG_NWD BIT(12) #define DESC_FLAG_CMD BIT(11) +#define BAM_NDP_REVISION_START 0x20 +#define BAM_NDP_REVISION_END 0x27 + struct bam_async_desc { struct virt_dma_desc vd; @@ -398,6 +401,7 @@ struct bam_device { /* dma start transaction tasklet */ struct tasklet_struct task; + u32 bam_revision; }; /** @@ -441,8 +445,10 @@ static void bam_reset(struct bam_device *bdev) writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL)); /* set descriptor threshold, start with 4 bytes */ - writel_relaxed(DEFAULT_CNT_THRSHLD, - bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD)); + if (in_range(bdev->bam_revision, BAM_NDP_REVISION_START, + BAM_NDP_REVISION_END)) + writel_relaxed(DEFAULT_CNT_THRSHLD, + bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD)); /* Enable default set of h/w workarounds, ie all except BAM_FULL_PIPE */ writel_relaxed(BAM_CNFG_BITS_DEFAULT, bam_addr(bdev, 0, BAM_CNFG_BITS)); @@ -1000,9 +1006,10 @@ static void bam_apply_new_config(struct bam_chan *bchan, maxburst = bchan->slave.src_maxburst; else maxburst = bchan->slave.dst_maxburst; - - writel_relaxed(maxburst, - bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD)); + if (in_range(bdev->bam_revision, BAM_NDP_REVISION_START, + BAM_NDP_REVISION_END)) + writel_relaxed(maxburst, + bam_addr(bdev, 0, BAM_DESC_CNT_TRSHLD)); } bchan->reconfigure = 0; @@ -1192,10 +1199,11 @@ static int bam_init(struct bam_device *bdev) u32 val; /* read revision and configuration information */ - if (!bdev->num_ees) { - val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)); + val = readl_relaxed(bam_addr(bdev, 0, BAM_REVISION)); + if (!bdev->num_ees) bdev->num_ees = (val >> NUM_EES_SHIFT) & NUM_EES_MASK; - } + + bdev->bam_revision = val & REVISION_MASK; /* check that configured EE is within range */ if (bdev->ee >= bdev->num_ees)