From 918b8646497b5dba6ae82d4a7325f01b258972b9 Mon Sep 17 00:00:00 2001 From: Alexander Shishkin Date: Fri, 21 Jun 2019 19:19:29 +0300 Subject: [PATCH] intel_th: msu: Fix single mode with disabled IOMMU Commit 4e0eaf239fb3 ("intel_th: msu: Fix single mode with IOMMU") switched the single mode code to use dma mapping pages obtained from the page allocator, but with IOMMU disabled, that may lead to using SWIOTLB bounce buffers and without additional sync'ing, produces empty trace buffers. Fix this by using a DMA32 GFP flag to the page allocation in single mode, as the device supports full 32-bit DMA addressing. Signed-off-by: Alexander Shishkin Fixes: 4e0eaf239fb3 ("intel_th: msu: Fix single mode with IOMMU") Reviewed-by: Andy Shevchenko Reported-by: Ammy Yi Cc: stable Link: https://lore.kernel.org/r/20190621161930.60785-4-alexander.shishkin@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/hwtracing/intel_th/msu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c index 6bfce03c6489..cfd48c81b9d9 100644 --- a/drivers/hwtracing/intel_th/msu.c +++ b/drivers/hwtracing/intel_th/msu.c @@ -667,7 +667,7 @@ static int msc_buffer_contig_alloc(struct msc *msc, unsigned long size) goto err_out; ret = -ENOMEM; - page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order); + page = alloc_pages(GFP_KERNEL | __GFP_ZERO | GFP_DMA32, order); if (!page) goto err_free_sgt;