About handling dma_mapping_error result after dma_map_*

[Haneen Mohammed <hamohammed.sa@gmail.com>]

Hello,

I have a question about handling dma_mapping_error result. Is it enough
to add a warning after it? Because I have found two missing
dma_mapping_error in the drm/via driver but I wasn't sure how to handle 
the return value if an error was found. Below is the code mentioned:

---
 drivers/gpu/drm/via/via_dmablit.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/via/via_dmablit.c b/drivers/gpu/drm/via/via_dmablit.c
index 98aae98..5c11756 100644
--- a/drivers/gpu/drm/via/via_dmablit.c
+++ b/drivers/gpu/drm/via/via_dmablit.c
@@ -132,12 +132,19 @@ via_map_blit_for_device(struct pci_dev *pdev,
 								VIA_PFN(first_addr)],
 						     VIA_PGOFF(cur_mem), remaining_len,
 						     vsg->direction);
+				if (dma_mapping_error(&pdev->dev,
+						      desc_ptr->mem_addr))
+					dev_warn(&pdev->dev, "DMA mapping failed\n");
+
 				desc_ptr->dev_addr = cur_fb;
 
 				desc_ptr->size = remaining_len;
 				desc_ptr->next = (uint32_t) next;
 				next = dma_map_single(&pdev->dev, desc_ptr, sizeof(*desc_ptr),
 						      DMA_TO_DEVICE);
+				if (dma_mapping_error(&pdev->dev,
+						      next))
+					dev_warn(&pdev->dev, "DMA mapping failed\n");
 				desc_ptr++;
 				if (++num_descriptors_this_page >= vsg->descriptors_per_page) {
 					num_descriptors_this_page = 0;
-- 
2.7.4

Thank you!
Haneen