From: Joerg Roedel <[email protected]> Print a warning when all allocation tries have been failed and the function is about to return NULL. This prepares for calling the function with __GFP_NOWARN to suppress allocation failure warnings before all fall-backs have failed.
Signed-off-by: Joerg Roedel <[email protected]> --- lib/swiotlb.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 4abda07..e0e9212 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -655,7 +655,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, */ phys_addr_t paddr = map_single(hwdev, 0, size, DMA_FROM_DEVICE); if (paddr == SWIOTLB_MAP_ERROR) - return NULL; + goto err_warn; ret = phys_to_virt(paddr); dev_addr = phys_to_dma(hwdev, paddr); @@ -669,7 +669,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, /* DMA_TO_DEVICE to avoid memcpy in unmap_single */ swiotlb_tbl_unmap_single(hwdev, paddr, size, DMA_TO_DEVICE); - return NULL; + goto err_warn; } } @@ -677,6 +677,13 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, memset(ret, 0, size); return ret; + +err_warn: + pr_warn("swiotlb: coherent allocation failed for device %s size=%zu\n", + dev_name(hwdev), size); + dump_stack(); + + return NULL; } EXPORT_SYMBOL(swiotlb_alloc_coherent); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
