Re: [PATCH v2 2/2] !!! FOR TESTING ONLY !!! dmaengine: pl330: add verbose message and set NR_DEFAULT_DESC to 1

From: Marek Szyprowski
Date: Tue Oct 17 2017 - 07:28:01 EST


Hi Alexander,

On 2017-10-04 13:37, Alexander Kochetkov wrote:
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>

Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>

Seems to be working fine on Exynos4412 OdroidU3 board:

# dmesg | grep pl330
[ÂÂÂ 0.725608] dma-pl330 12680000.pdma: Loaded driver for PL330 DMAC-141330
[ÂÂÂ 0.725629] dma-pl330 12680000.pdma:ÂÂÂÂÂÂÂÂ DBUFF-32x4bytes Num_Chans-8 Num_Peri-32 Num_Events-32
[ÂÂÂ 0.731338] dma-pl330 12690000.pdma: Loaded driver for PL330 DMAC-141330
[ÂÂÂ 0.731357] dma-pl330 12690000.pdma:ÂÂÂÂÂÂÂÂ DBUFF-32x4bytes Num_Chans-8 Num_Peri-32 Num_Events-32
[ÂÂÂ 0.733097] dma-pl330 12850000.mdma: Loaded driver for PL330 DMAC-141330
[ÂÂÂ 0.733115] dma-pl330 12850000.mdma:ÂÂÂÂÂÂÂÂ DBUFF-64x8bytes Num_Chans-8 Num_Peri-1 Num_Events-32
[ÂÂ 98.353073] dma-pl330 12680000.pdma: pl330_get_desc:2460 Allocated one more descriptor
[ÂÂ 98.360970] dma-pl330 12680000.pdma: pl330_get_desc:2460 Allocated one more descriptor
[ÂÂ 98.368867] dma-pl330 12680000.pdma: pl330_get_desc:2460 Allocated one more descriptor

---
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 */

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland