From 560000d619ef162568746ce287f0c725e24ea967 Mon Sep 17 00:00:00 2001 From: Li RongQing Date: Wed, 3 Jun 2026 09:37:23 +0800 Subject: [PATCH] dma-mapping: direct: fix missing mapping for THRU_HOST_BRIDGE segments In dma_direct_map_sg(), the case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE incorrectly used 'break' instead of falling through to MAP_NONE. As a result, segments traversing the host bridge skipped the required dma_direct_map_phys() call entirely, leaving sg->dma_address uninitialized and leading to DMA failures. Fix this by using 'fallthrough;'. Fixes: a25e7962db0d79 ("PCI/P2PDMA: Refactor the p2pdma mapping helpers") Reviewed-by: Logan Gunthorpe Signed-off-by: Li RongQing Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20260603013723.2439-1-lirongqing@baidu.com --- kernel/dma/direct.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 583c5922bca2..4391b797d4db 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -476,7 +476,7 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents, * must be mapped with CPU physical address and not PCI * bus addresses. */ - break; + fallthrough; case PCI_P2PDMA_MAP_NONE: need_sync = true; sg->dma_address = dma_direct_map_phys(dev, sg_phys(sg),