From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756435AbcIVKZU (ORCPT ); Thu, 22 Sep 2016 06:25:20 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:39536 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752307AbcIVKZT (ORCPT ); Thu, 22 Sep 2016 06:25:19 -0400 From: Mark Brown To: Nikita Yushchenko Cc: Mark Brown , Mark Brown , Greg Kroah-Hartman , Kuninori Morimoto , Xiubo Li , Dan Carpenter , Jon Ringle , Chen-Yu Tsai , "David S. Miller" , linux-kernel@vger.kernel.org, Chris Healy In-Reply-To: <1474534945-19648-1-git-send-email-nikita.yoush@cogentembedded.com> Message-Id: Date: Thu, 22 Sep 2016 11:24:56 +0100 X-SA-Exim-Connect-IP: 2a01:348:6:8808:fab::3 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Applied "regmap: fix deadlock on _regmap_raw_write() error path" to the regmap tree X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: No (on mezzanine.sirena.org.uk); Unknown failure Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The patch regmap: fix deadlock on _regmap_raw_write() error path has been applied to the regmap tree at git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark >>From f0aa1ce6259eb65f53f969b3250c1d0aac84f30b Mon Sep 17 00:00:00 2001 From: Nikita Yushchenko Date: Thu, 22 Sep 2016 12:02:25 +0300 Subject: [PATCH] regmap: fix deadlock on _regmap_raw_write() error path Commit 815806e39bf6 ("regmap: drop cache if the bus transfer error") added a call to regcache_drop_region() to error path in _regmap_raw_write(). However that path runs with regmap lock taken, and regcache_drop_region() tries to re-take it, causing a deadlock. Fix that by calling map->cache_ops->drop() directly. Signed-off-by: Nikita Yushchenko Signed-off-by: Mark Brown --- drivers/base/regmap/regmap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 25d26bb18970..e964d068874d 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -1475,7 +1475,11 @@ int _regmap_raw_write(struct regmap *map, unsigned int reg, kfree(buf); } else if (ret != 0 && !map->cache_bypass && map->format.parse_val) { - regcache_drop_region(map, reg, reg + 1); + /* regcache_drop_region() takes lock that we already have, + * thus call map->cache_ops->drop() directly + */ + if (map->cache_ops && map->cache_ops->drop) + map->cache_ops->drop(map, reg, reg + 1); } trace_regmap_hw_write_done(map, reg, val_len / map->format.val_bytes); -- 2.8.1