Commit e521f516 authored by Casey Connolly's avatar Casey Connolly Committed by Vinod Koul
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dmaengine: Revert "dmaengine: qcom: bam_dma: Avoid writing unavailable register" 



This commit causes a hard crash on sdm845 and likely other platforms.
Revert it until a proper fix is found.

This reverts commit 57a7138d: ("dmaengine: qcom: bam_dma: Avoid writing
unavailable register")

Signed-off-by: default avatarCaleb Connolly <caleb.connolly@linaro.org>
Fixes: 57a7138d ("dmaengine: qcom: bam_dma: Avoid writing unavailable register")
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on sdm845-DB845c
Tested-by: default avatarDavid Heidelberg <david@ixit.cz>
Link: https://lore.kernel.org/r/20250208223112.142567-1-caleb.connolly@linaro.org


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 76ed9b7d

drivers/dma/qcom/bam_dma.c

+8 −16
Original line number Diff line number Diff line
@@ -59,9 +59,6 @@ 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;
@@ -401,7 +398,6 @@ struct bam_device { 


	/* dma start transaction tasklet */

	struct tasklet_struct task;

	u32 bam_revision;

};



/**
@@ -445,8 +441,6 @@ static void bam_reset(struct bam_device *bdev) 
	writel_relaxed(val, bam_addr(bdev, 0, BAM_CTRL));



	/* set descriptor threshold, start with 4 bytes */

	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));
@@ -1006,8 +1000,7 @@ static void bam_apply_new_config(struct bam_chan *bchan, 
			maxburst = bchan->slave.src_maxburst;

		else

			maxburst = bchan->slave.dst_maxburst;

		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));

	}
@@ -1199,11 +1192,10 @@ 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));

	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)