Sometimes it is good to know when your mapping failed. Fixes: cafaf14a5d8f ("io-mapping: Always create a struct to hold metadata about the io-mapping" Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Michael J. Ruhl <michael.j.ruhl@xxxxxxxxx> --- include/linux/io-mapping.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h index 0beaa3eba155..5641e06cbcf7 100644 --- a/include/linux/io-mapping.h +++ b/include/linux/io-mapping.h @@ -118,7 +118,7 @@ io_mapping_init_wc(struct io_mapping *iomap, iomap->prot = pgprot_noncached(PAGE_KERNEL); #endif - return iomap; + return iomap->iomem ? iomap : NULL; } static inline void -- 2.21.0