From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966514Ab3HIKKD (ORCPT ); Fri, 9 Aug 2013 06:10:03 -0400 Received: from demumfd001.nsn-inter.net ([93.183.12.32]:12113 "EHLO demumfd001.nsn-inter.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965601Ab3HIKKA (ORCPT ); Fri, 9 Aug 2013 06:10:00 -0400 Message-ID: <5204BFD0.5080305@nsn.com> Date: Fri, 09 Aug 2013 12:09:20 +0200 From: Ionut Nicu User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Mark Brown CC: Greg Kroah-Hartman , linux-kernel@vger.kernel.org Subject: [PATCH 3/3] regmap: regcache: allow read-only regs to be cached Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-purgate-type: clean X-purgate-Ad: Categorized by eleven eXpurgate (R) http://www.eleven.de X-purgate: clean X-purgate: This mail is considered clean (visit http://www.eleven.de for further information) X-purgate-size: 1570 X-purgate-ID: 151667::1376042964-00003561-337A0975/0-0/0-0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The regmap_writeable() check should not be done in regcache_write() because this prevents read-only registers to be cached. After a read on a read-only register its value will not be stored in the cache and the next time someone will try to read it the value will be read from the bus instead of the cache. Instead the regmap_writeable() check should be done in _regmap_write() to prevent callers from writing to read-only registers. Signed-off-by: Ionut Nicu --- drivers/base/regmap/regcache.c | 3 --- drivers/base/regmap/regmap.c | 3 +++ 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c index 3455f83..e2abd05 100644 --- a/drivers/base/regmap/regcache.c +++ b/drivers/base/regmap/regcache.c @@ -241,9 +241,6 @@ int regcache_write(struct regmap *map, BUG_ON(!map->cache_ops); - if (!regmap_writeable(map, reg)) - return -EIO; - if (!regmap_volatile(map, reg)) return map->cache_ops->write(map, reg, value); diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index fa76b61..42b45ac 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -1267,6 +1267,9 @@ int _regmap_write(struct regmap *map, unsigned int reg, int ret; void *context = _regmap_map_get_context(map); + if (!regmap_writeable(map, reg)) + return -EIO; + if (!map->cache_bypass && !map->defer_caching) { ret = regcache_write(map, reg, val); if (ret != 0) -- 1.7.1