Re: [PATCH] coresight: tmc: Configure DMA mask appropriately
From: Suzuki K Poulose
Date: Fri May 19 2017 - 09:29:21 EST
On 18/05/17 16:14, Robin Murphy wrote:
Before making any DMA API calls, the ETR driver should really be setting
its masks to ensure that DMA is possible. Especially since it can
address more than the 32-bit default mask set by the AMBA bus code.
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
drivers/hwtracing/coresight/coresight-tmc.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-tmc.c b/drivers/hwtracing/coresight/coresight-tmc.c
index d8517d2a968c..864488793f09 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.c
+++ b/drivers/hwtracing/coresight/coresight-tmc.c
@@ -362,6 +362,13 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
desc.type = CORESIGHT_DEV_TYPE_SINK;
desc.subtype.sink_subtype = CORESIGHT_DEV_SUBTYPE_SINK_BUFFER;
desc.ops = &tmc_etr_cs_ops;
+ /*
+ * ETR configuration uses a 40-bit AXI master in place of
+ * the embedded SRAM of ETB/ETF.
+ */
+ ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(40));
+ if (ret)
+ goto out;
} else {
desc.type = CORESIGHT_DEV_TYPE_LINKSINK;
desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_FIFO;
Tested this patch on Juno, with the SMMU enabled for the etr. I was able to
allocate 32M using (the CMA was only 16M). FWIW :
Tested-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>