When allocating a buffer to support asynchronous comedi commands, if a
DMA coherent buffer was requested but `CONFIG_HAS_DMA` is undefined,
bail out of local helper function `__comedi_buf_alloc()` with an error
message.
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
drivers/staging/comedi/comedi_buf.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/staging/comedi/comedi_buf.c b/drivers/staging/comedi/comedi_buf.c
index b6cd67a..d4be0e6 100644
--- a/drivers/staging/comedi/comedi_buf.c
+++ b/drivers/staging/comedi/comedi_buf.c
@@ -76,6 +76,12 @@ static void __comedi_buf_alloc(struct comedi_device *dev,
struct comedi_buf_page *buf;
unsigned i;
+ if (!IS_ENABLED(CONFIG_HAS_DMA) && s->async_dma_dir != DMA_NONE) {
+ dev_err(dev->class_dev,
+ "dma buffer allocation not supported\n");
+ return;
+ }
+
async->buf_page_list = vzalloc(sizeof(*buf) * n_pages);
if (async->buf_page_list)
pages = vmalloc(sizeof(struct page *) * n_pages);
--
1.8.1.5
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