From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764411AbcIOJjz (ORCPT ); Thu, 15 Sep 2016 05:39:55 -0400 Received: from relay1.mentorg.com ([192.94.38.131]:55437 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755004AbcIOJjv (ORCPT ); Thu, 15 Sep 2016 05:39:51 -0400 From: Mark Craske To: Greg Kroah-Hartman CC: , "George G. Davis" , Jiada Wang Subject: [PATCH v1 1/2] drivers: dma-coherent: Fix DMA coherent size for less than page Date: Thu, 15 Sep 2016 10:39:58 +0100 Message-ID: <1473932399-23224-2-git-send-email-Mark_Craske@mentor.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1473932399-23224-1-git-send-email-Mark_Craske@mentor.com> References: <1473932399-23224-1-git-send-email-Mark_Craske@mentor.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "George G. Davis" We fix a bug in dma_mmap_from_coherent() that appears when we map non page aligned DMA memory. It cuts off the non aligned part (this is different to dma_alloc_coherent() that always rounds up to full pages). So for mappings of less than a page we get -ENXIO as dma_mmap_from_coherent() assumes we want to map zero pages. Signed-off-by: George G. Davis Signed-off-by: Jiada Wang Signed-off-by: Mark Craske --- drivers/base/dma-coherent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c index bdf28f7..abd83b7 100644 --- a/drivers/base/dma-coherent.c +++ b/drivers/base/dma-coherent.c @@ -262,7 +262,7 @@ int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma, unsigned long off = vma->vm_pgoff; int start = (vaddr - mem->virt_base) >> PAGE_SHIFT; int user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; - int count = size >> PAGE_SHIFT; + int count = PAGE_ALIGN(size) >> PAGE_SHIFT; *ret = -ENXIO; if (off < count && user_count <= count - off) { -- 1.7.9.5