From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753536AbaIPLnu (ORCPT ); Tue, 16 Sep 2014 07:43:50 -0400 Received: from mga09.intel.com ([134.134.136.24]:53291 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752824AbaIPLnt (ORCPT ); Tue, 16 Sep 2014 07:43:49 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,534,1406617200"; d="scan'208";a="603517414" From: Jarkko Nikula To: Mark Brown Cc: linux-kernel@vger.kernel.org, Jarkko Nikula Subject: [PATCH] regmap: cache: Do not fail silently from regcache_sync calls Date: Tue, 16 Sep 2014 14:04:14 +0300 Message-Id: <1410865454-30102-1-git-send-email-jarkko.nikula@linux.intel.com> X-Mailer: git-send-email 2.1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Call stack of regcache_sync calls may not emit any error message even if operation was cancelled due an error in I/O driver. One such a silent error is for instance if I2C bus driver doesn't receive ACK from the I2C device and returns -EREMOTEIO. Since many users of regcache_sync() don't check and print the error there is no any indication that HW registers are potentially out of sync. Signed-off-by: Jarkko Nikula --- I noticed this silent failure when doing commit f4821e8e8e95 ("ASoC: rt5640: Do not allow regmap to use bulk read-write operations") but forgot to send a patch. I was thinking should the error prints be in lower level, e.g. _regmap_raw_write, but maybe it's good to have sync errors printed explicitly? --- drivers/base/regmap/regcache.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c index 5617da6dc898..f1280dc356d0 100644 --- a/drivers/base/regmap/regcache.c +++ b/drivers/base/regmap/regcache.c @@ -269,8 +269,11 @@ static int regcache_default_sync(struct regmap *map, unsigned int min, map->cache_bypass = 1; ret = _regmap_write(map, reg, val); map->cache_bypass = 0; - if (ret) + if (ret) { + dev_err(map->dev, "Unable to sync register %#x. %d\n", + reg, ret); return ret; + } dev_dbg(map->dev, "Synced register %#x, value %#x\n", reg, val); } @@ -615,8 +618,11 @@ static int regcache_sync_block_single(struct regmap *map, void *block, ret = _regmap_write(map, regtmp, val); map->cache_bypass = 0; - if (ret != 0) + if (ret != 0) { + dev_err(map->dev, "Unable to sync register %#x. %d\n", + regtmp, ret); return ret; + } dev_dbg(map->dev, "Synced register %#x, value %#x\n", regtmp, val); } @@ -641,6 +647,9 @@ static int regcache_sync_block_raw_flush(struct regmap *map, const void **data, map->cache_bypass = 1; ret = _regmap_raw_write(map, base, *data, count * val_bytes); + if (ret) + dev_err(map->dev, "Unable to sync registers %#x-%#x. %d\n", + base, cur - map->reg_stride, ret); map->cache_bypass = 0; -- 2.1.0