From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754719AbaBTQfG (ORCPT ); Thu, 20 Feb 2014 11:35:06 -0500 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:38573 "EHLO opensource.wolfsonmicro.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752687AbaBTQfF (ORCPT ); Thu, 20 Feb 2014 11:35:05 -0500 From: Charles Keepax To: lee.jones@linaro.org Cc: sameo@linux.intel.com, broonie@kernel.org, patches@opensource.wolfsonmicro.com, linux-kernel@vger.kernel.org Subject: [PATCH] mfd: wm5102: Remove cache_bypass from manual register patching Date: Thu, 20 Feb 2014 16:26:48 +0000 Message-Id: <1392913608-23479-1-git-send-email-ckeepax@opensource.wolfsonmicro.com> X-Mailer: git-send-email 1.7.2.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On the wm5102 the register patches are applied manually, rather than by the regmap core. This application is wrapped in calls to regcache_cache_bypass. However, this is dangerous as other threads may be accessing the hardware at the same time as the pm_runtime operations and if they do so during the period whilst cache_bypass is enabled those writes will miss the cache when they shouldn't. As the cache_bypass is not strictly necessary for applying the patches (the device is always powered on whilst it is applied) remove the calls to regcache_cache_bypass to avoid this situation. Signed-off-by: Charles Keepax --- drivers/mfd/arizona-core.c | 4 ---- drivers/mfd/wm5102-tables.c | 10 +++------- 2 files changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c index a45aab9..1c3ae57 100644 --- a/drivers/mfd/arizona-core.c +++ b/drivers/mfd/arizona-core.c @@ -251,8 +251,6 @@ static int arizona_apply_hardware_patch(struct arizona* arizona) unsigned int fll, sysclk; int ret, err; - regcache_cache_bypass(arizona->regmap, true); - /* Cache existing FLL and SYSCLK settings */ ret = regmap_read(arizona->regmap, ARIZONA_FLL1_CONTROL_1, &fll); if (ret != 0) { @@ -322,8 +320,6 @@ err_fll: err); } - regcache_cache_bypass(arizona->regmap, false); - if (ret != 0) return ret; else diff --git a/drivers/mfd/wm5102-tables.c b/drivers/mfd/wm5102-tables.c index 187ee86..b9556bc 100644 --- a/drivers/mfd/wm5102-tables.c +++ b/drivers/mfd/wm5102-tables.c @@ -81,7 +81,7 @@ static const struct reg_default wm5102_revb_patch[] = { int wm5102_patch(struct arizona *arizona) { const struct reg_default *wm5102_patch; - int ret = 0; + int ret; int i, patch_size; switch (arizona->rev) { @@ -93,21 +93,17 @@ int wm5102_patch(struct arizona *arizona) patch_size = ARRAY_SIZE(wm5102_revb_patch); } - regcache_cache_bypass(arizona->regmap, true); - for (i = 0; i < patch_size; i++) { ret = regmap_write(arizona->regmap, wm5102_patch[i].reg, wm5102_patch[i].def); if (ret != 0) { dev_err(arizona->dev, "Failed to write %x = %x: %d\n", wm5102_patch[i].reg, wm5102_patch[i].def, ret); - goto out; + return ret; } } -out: - regcache_cache_bypass(arizona->regmap, false); - return ret; + return 0; } static const struct regmap_irq wm5102_aod_irqs[ARIZONA_NUM_IRQ] = { -- 1.7.2.5