From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754141Ab2A3QDq (ORCPT ); Mon, 30 Jan 2012 11:03:46 -0500 Received: from mail.work-microwave.de ([62.245.205.51]:31100 "EHLO work-microwave.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754079Ab2A3QDP (ORCPT ); Mon, 30 Jan 2012 11:03:15 -0500 From: Roland Stigge To: w.sang@pengutronix.de, bangaragiri.g@nxp.com, srinivas.bakki@nxp.com, sundarapandian.andithevar@nxp.com, linus.walleij@linaro.org, linux-kernel@vger.kernel.org, kevin.wells@nxp.com, grant.likely@secretlab.ca, linux-arm-kernel@lists.infradead.org Cc: Roland Stigge Subject: [PATCH v2 7/7] LPC32xx: clock.c: Fix mutex lock issues Date: Mon, 30 Jan 2012 17:02:06 +0100 Message-Id: <1327939327-7799-7-git-send-email-stigge@antcom.de> X-Mailer: git-send-email 1.7.8.3 In-Reply-To: <1327939327-7799-1-git-send-email-stigge@antcom.de> References: <1327939327-7799-1-git-send-email-stigge@antcom.de> X-FEAS-SYSTEM-WL: rst@work-microwave.de, 192.168.11.78 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch fixes the mutex issue in clock.c, as done in Kevin Wells' original driver update: In some cases, the clock drivers could grab a mutex twice in an improper context. This patch changes the mutex mechanism to a simple irq lock/unlock mechanism and removes un-needed locks from some functions. (See also git.lpclinux.com) Signed-off-by: Roland Stigge diff --git a/arch/arm/mach-lpc32xx/clock.c b/arch/arm/mach-lpc32xx/clock.c index f49638a..aceb88a 100644 --- a/arch/arm/mach-lpc32xx/clock.c +++ b/arch/arm/mach-lpc32xx/clock.c @@ -99,11 +99,12 @@ #include "clock.h" #include "common.h" +static DEFINE_SPINLOCK(global_clkregs_lock); + static int usb_pll_enable, usb_pll_valid; static struct clk clk_armpll; static struct clk clk_usbpll; -static DEFINE_MUTEX(clkm_lock); /* * Post divider values for PLLs based on selected register value @@ -934,16 +935,6 @@ static struct clk clk_lcd = { .enable_mask = LPC32XX_CLKPWR_LCDCTRL_CLK_EN, }; -static inline void clk_lock(void) -{ - mutex_lock(&clkm_lock); -} - -static inline void clk_unlock(void) -{ - mutex_unlock(&clkm_lock); -} - static void local_clk_disable(struct clk *clk) { /* Don't attempt to disable clock if it has no users */ @@ -988,10 +979,11 @@ static int local_clk_enable(struct clk *clk) int clk_enable(struct clk *clk) { int ret; + unsigned long flags; - clk_lock(); + spin_lock_irqsave(&global_clkregs_lock, flags); ret = local_clk_enable(clk); - clk_unlock(); + spin_unlock_irqrestore(&global_clkregs_lock, flags); return ret; } @@ -1002,9 +994,11 @@ EXPORT_SYMBOL(clk_enable); */ void clk_disable(struct clk *clk) { - clk_lock(); + unsigned long flags; + + spin_lock_irqsave(&global_clkregs_lock, flags); local_clk_disable(clk); - clk_unlock(); + spin_unlock_irqrestore(&global_clkregs_lock, flags); } EXPORT_SYMBOL(clk_disable); @@ -1013,13 +1007,7 @@ EXPORT_SYMBOL(clk_disable); */ unsigned long clk_get_rate(struct clk *clk) { - unsigned long rate; - - clk_lock(); - rate = clk->get_rate(clk); - clk_unlock(); - - return rate; + return clk->get_rate(clk); } EXPORT_SYMBOL(clk_get_rate); @@ -1035,11 +1023,8 @@ int clk_set_rate(struct clk *clk, unsigned long rate) * the actual rate set as part of the peripheral dividers * instead of high level clock control */ - if (clk->set_rate) { - clk_lock(); + if (clk->set_rate) ret = clk->set_rate(clk, rate); - clk_unlock(); - } return ret; } @@ -1050,15 +1035,11 @@ EXPORT_SYMBOL(clk_set_rate); */ long clk_round_rate(struct clk *clk, unsigned long rate) { - clk_lock(); - if (clk->round_rate) rate = clk->round_rate(clk, rate); else rate = clk->get_rate(clk); - clk_unlock(); - return rate; } EXPORT_SYMBOL(clk_round_rate);