Commit add verbose output to pl330 showing what changes introduced by commit 1/2 from series work as expected. You should see similar output running modified kernel: The patch tested on rk3188 radxdarock. Could someone else test it on other hardware with pl330 DMA? root@host:~# dmesg | grep pl330 [ 0.277520] dma-pl330 20018000.dma-controller: Loaded driver for PL330 DMAC-241330 [ 0.277538] dma-pl330 20018000.dma-controller: DBUFF-32x8bytes Num_Chans-6 Num_Peri-12 Num_Events-12 [ 0.279894] dma-pl330 20078000.dma-controller: Loaded driver for PL330 DMAC-241330 [ 0.279910] dma-pl330 20078000.dma-controller: DBUFF-64x8bytes Num_Chans-7 Num_Peri-20 Num_Events-14 [ 1.344804] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor [ 1.344832] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor [ 1.344853] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor [ 1.344873] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor [ 1.344893] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor [ 1.344912] dma-pl330 20078000.dma-controller: pl330_get_desc:2458 Allocated one more descriptor --- rest of similar lines omitted --- Signed-off-by: Alexander Kochetkov <al.kochet@xxxxxxxxx> --- drivers/dma/pl330.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index deec4a4..3441c16 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -266,7 +266,7 @@ enum pl330_byteswap { /* The number of default descriptors */ -#define NR_DEFAULT_DESC 16 +#define NR_DEFAULT_DESC 1 /* Delay for runtime PM autosuspend, ms */ #define PL330_AUTOSUSPEND_DELAY 20 @@ -2455,6 +2455,9 @@ static struct dma_pl330_desc *pl330_get_desc(struct dma_pl330_chan *pch) desc = pluck_desc(&pool, &lock); WARN_ON(!desc || !list_empty(&pool)); + + dev_err(pch->dmac->ddma.dev, "%s:%d Allocated one more descriptor\n", + __func__, __LINE__); } /* Initialize the descriptor */ -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html