From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758296Ab0IGUy2 (ORCPT ); Tue, 7 Sep 2010 16:54:28 -0400 Received: from hqemgate03.nvidia.com ([216.228.121.140]:18631 "EHLO hqemgate03.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757092Ab0IGUyX (ORCPT ); Tue, 7 Sep 2010 16:54:23 -0400 X-PGP-Universal: processed; by hqnvupgp02.nvidia.com on Tue, 07 Sep 2010 13:53:20 -0700 From: Gary King To: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org, tj@kernel.org, linux-kernel@vger.kernel.org, Gary King Subject: [PATCH] bounce: call flush_dcache_page after bounce_copy_vec Date: Tue, 7 Sep 2010 13:45:34 -0700 Message-Id: <1283892334-9238-1-git-send-email-gking@nvidia.com> X-Mailer: git-send-email 1.7.0.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I have been seeing problems on Tegra 2 (ARMv7 SMP) systems with HIGHMEM enabled on 2.6.35 (plus some patches targetted at 2.6.36 to perform cache maintenance lazily), and the root cause appears to be that the mm bouncing code is calling flush_dcache_page before it copies the bounce buffer into the bio. The patch below reorders these two operations, and eliminates numerous arbitrary application crashes on my dev system. Gary -- >>From 678c9bca8d8a8f254f28af91e69fad3aa1be7593 Mon Sep 17 00:00:00 2001 From: Gary King Date: Mon, 6 Sep 2010 15:37:12 -0700 Subject: bounce: call flush_dcache_page after bounce_copy_vec the bounced page needs to be flushed after data is copied into it, to ensure that architecture implementations can synchronize instruction and data caches if necessary. Signed-off-by: Gary King --- mm/bounce.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/mm/bounce.c b/mm/bounce.c index 13b6dad..1481de6 100644 --- a/mm/bounce.c +++ b/mm/bounce.c @@ -116,8 +116,8 @@ static void copy_to_high_bio_irq(struct bio *to, struct bio *from) */ vfrom = page_address(fromvec->bv_page) + tovec->bv_offset; - flush_dcache_page(tovec->bv_page); bounce_copy_vec(tovec, vfrom); + flush_dcache_page(tovec->bv_page); } } -- 1.7.0.4