[PATCH v5 1/4] dmaengine: dw: platform: check nr_masters to be non-zero

From: Andy Shevchenko
Date: Thu Apr 21 2016 - 11:11:08 EST


The nr_masters value equal to 0 is invalid since this DMA controller has to
have at least one master.

Check this before we proceed with the rest of properties.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/dma/dw/platform.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/dw/platform.c b/drivers/dma/dw/platform.c
index 23616c5..922b102 100644
--- a/drivers/dma/dw/platform.c
+++ b/drivers/dma/dw/platform.c
@@ -103,6 +103,7 @@ dw_dma_parse_dt(struct platform_device *pdev)
struct device_node *np = pdev->dev.of_node;
struct dw_dma_platform_data *pdata;
u32 tmp, arr[DW_DMA_MAX_NR_MASTERS];
+ u32 nr_masters;
u32 nr_channels;

if (!np) {
@@ -110,6 +111,13 @@ dw_dma_parse_dt(struct platform_device *pdev)
return NULL;
}

+ if (of_property_read_u32(np, "dma-masters", &nr_masters))
+ return NULL;
+ if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)
+ return NULL;
+
+ pdata->nr_masters = nr_masters;
+
if (of_property_read_u32(np, "dma-channels", &nr_channels))
return NULL;

@@ -131,17 +139,10 @@ dw_dma_parse_dt(struct platform_device *pdev)
if (!of_property_read_u32(np, "block_size", &tmp))
pdata->block_size = tmp;

- if (!of_property_read_u32(np, "dma-masters", &tmp)) {
- if (tmp > DW_DMA_MAX_NR_MASTERS)
- return NULL;
-
- pdata->nr_masters = tmp;
- }
-
- if (!of_property_read_u32_array(np, "data_width", arr,
- pdata->nr_masters))
- for (tmp = 0; tmp < pdata->nr_masters; tmp++)
+ if (!of_property_read_u32_array(np, "data_width", arr, nr_masters)) {
+ for (tmp = 0; tmp < nr_masters; tmp++)
pdata->data_width[tmp] = arr[tmp];
+ }

return pdata;
}
--
2.8.0.rc3