From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: [PATCH 3/5] OMAP: hwmod: add option for no locking in idle/enable paths Date: Thu, 27 May 2010 14:13:34 -0700 Message-ID: <1274994816-30335-4-git-send-email-khilman@deeprootsystems.com> References: <1274994816-30335-1-git-send-email-khilman@deeprootsystems.com> Return-path: Received: from mail-pw0-f46.google.com ([209.85.160.46]:45584 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756733Ab0E0VNp (ORCPT ); Thu, 27 May 2010 17:13:45 -0400 Received: by mail-pw0-f46.google.com with SMTP id 7so248809pwi.19 for ; Thu, 27 May 2010 14:13:44 -0700 (PDT) In-Reply-To: <1274994816-30335-1-git-send-email-khilman@deeprootsystems.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: linux-omap@vger.kernel.org Some hwmods may be idled/enabled directly from within the core idle/suspend path. Since interrupts are already disabled here, the mutex-based locking in hwmod can sleep and will cause potential deadlocks. To fix, add a hwmod flag HWMOD_NO_IDLE_LOCKING which indicates to the hwmod core that no locking should be done during the idle/enable paths for this hwmod. Signed-off-by: Kevin Hilman --- arch/arm/mach-omap2/omap_hwmod.c | 16 ++++++++++++---- arch/arm/plat-omap/include/plat/omap_hwmod.h | 1 + 2 files changed, 13 insertions(+), 4 deletions(-) diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c index 77fef90..1ee2fb2 100644 --- a/arch/arm/mach-omap2/omap_hwmod.c +++ b/arch/arm/mach-omap2/omap_hwmod.c @@ -1304,9 +1304,13 @@ int omap_hwmod_enable(struct omap_hwmod *oh) if (!oh) return -EINVAL; - mutex_lock(&omap_hwmod_mutex); + if (!(oh->flags & HWMOD_NO_IDLE_LOCKING)) + mutex_lock(&omap_hwmod_mutex); + r = _enable(oh); - mutex_unlock(&omap_hwmod_mutex); + + if (!(oh->flags & HWMOD_NO_IDLE_LOCKING)) + mutex_unlock(&omap_hwmod_mutex); return r; } @@ -1323,9 +1327,13 @@ int omap_hwmod_idle(struct omap_hwmod *oh) if (!oh) return -EINVAL; - mutex_lock(&omap_hwmod_mutex); + if (!(oh->flags & HWMOD_NO_IDLE_LOCKING)) + mutex_lock(&omap_hwmod_mutex); + _idle(oh); - mutex_unlock(&omap_hwmod_mutex); + + if (!(oh->flags & HWMOD_NO_IDLE_LOCKING)) + mutex_unlock(&omap_hwmod_mutex); return 0; } diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h index 0eccc09..cc3f9a7 100644 --- a/arch/arm/plat-omap/include/plat/omap_hwmod.h +++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h @@ -360,6 +360,7 @@ struct omap_hwmod_omap4_prcm { #define HWMOD_NO_OCP_AUTOIDLE (1 << 4) #define HWMOD_SET_DEFAULT_CLOCKACT (1 << 5) #define HWMOD_NO_IDLEST (1 << 6) +#define HWMOD_NO_IDLE_LOCKING (1 << 7) /* * omap_hwmod._int_flags definitions -- 1.7.0.2