From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932478AbaHVODF (ORCPT ); Fri, 22 Aug 2014 10:03:05 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:43958 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756522AbaHVOC7 (ORCPT ); Fri, 22 Aug 2014 10:02:59 -0400 From: Nishanth Menon To: Santosh Shilimkar , Tony Lindgren , Tero Kristo , Paul Walmsley CC: Kevin Hilman , , , , Keerthy , =?UTF-8?q?Beno=C3=AEt=20Cousson?= , Nishanth Menon Subject: [PATCH 02/10] ARM: OMAP5 / DRA7: PM: Set MPUSS-EMIF clock-domain static dependency Date: Fri, 22 Aug 2014 09:02:26 -0500 Message-ID: <1408716154-26101-3-git-send-email-nm@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1408716154-26101-1-git-send-email-nm@ti.com> References: <1408716154-26101-1-git-send-email-nm@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Santosh Shilimkar With EMIF clock-domain put under hardware supervised control, memory corruption and untraceable crashes are observed on OMAP5. Further investigation revealed that there is a weakness in the PRCM on this specific dynamic depedency. The recommendation is to set MPUSS static dependency towards EMIF clock-domain to avoid issues. This recommendation holds good for DRA7 family of devices as well. Signed-off-by: Santosh Shilimkar [rnayak@ti.com: DRA7] Signed-off-by: Rajendra Nayak [nm@ti.com: conflict resolution, dra7] Signed-off-by: Nishanth Menon --- arch/arm/mach-omap2/pm44xx.c | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm44xx.c index 0dda6cf..b6f243d 100644 --- a/arch/arm/mach-omap2/pm44xx.c +++ b/arch/arm/mach-omap2/pm44xx.c @@ -203,6 +203,32 @@ static inline int omap4_init_static_deps(void) } /** + * omap5_dra7_init_static_deps - Init static clkdm dependencies on OMAP5 and + * DRA7 + * + * The dynamic dependency between MPUSS -> EMIF is broken and has + * not worked as expected. The hardware recommendation is to + * enable static dependencies for these to avoid system + * lock ups or random crashes. + */ +static inline int omap5_dra7_init_static_deps(void) +{ + struct clockdomain *mpuss_clkdm, *emif_clkdm; + int ret; + + mpuss_clkdm = clkdm_lookup("mpu_clkdm"); + emif_clkdm = clkdm_lookup("emif_clkdm"); + if (!mpuss_clkdm || !emif_clkdm) + return -EINVAL; + + ret = clkdm_add_wkdep(mpuss_clkdm, emif_clkdm); + if (ret) + pr_err("Failed to add MPUSS -> EMIF wakeup dependency\n"); + + return ret; +} + +/** * omap4_pm_init_early - Does early initialization necessary for OMAP4+ devices * * Initializes basic stuff for power management functionality. @@ -239,10 +265,14 @@ int __init omap4_pm_init(void) goto err2; } - if (cpu_is_omap44xx()) { + if (cpu_is_omap44xx()) ret = omap4_init_static_deps(); - if (ret) - goto err2; + else if (soc_is_omap54xx() || soc_is_dra7xx()) + ret = omap5_dra7_init_static_deps(); + + if (ret) { + pr_err("Failed to initialise static dependencies.\n"); + goto err2; } ret = omap4_mpuss_init(); -- 1.7.9.5 From mboxrd@z Thu Jan 1 00:00:00 1970 From: nm@ti.com (Nishanth Menon) Date: Fri, 22 Aug 2014 09:02:26 -0500 Subject: [PATCH 02/10] ARM: OMAP5 / DRA7: PM: Set MPUSS-EMIF clock-domain static dependency In-Reply-To: <1408716154-26101-1-git-send-email-nm@ti.com> References: <1408716154-26101-1-git-send-email-nm@ti.com> Message-ID: <1408716154-26101-3-git-send-email-nm@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Santosh Shilimkar With EMIF clock-domain put under hardware supervised control, memory corruption and untraceable crashes are observed on OMAP5. Further investigation revealed that there is a weakness in the PRCM on this specific dynamic depedency. The recommendation is to set MPUSS static dependency towards EMIF clock-domain to avoid issues. This recommendation holds good for DRA7 family of devices as well. Signed-off-by: Santosh Shilimkar [rnayak at ti.com: DRA7] Signed-off-by: Rajendra Nayak [nm at ti.com: conflict resolution, dra7] Signed-off-by: Nishanth Menon --- arch/arm/mach-omap2/pm44xx.c | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm44xx.c index 0dda6cf..b6f243d 100644 --- a/arch/arm/mach-omap2/pm44xx.c +++ b/arch/arm/mach-omap2/pm44xx.c @@ -203,6 +203,32 @@ static inline int omap4_init_static_deps(void) } /** + * omap5_dra7_init_static_deps - Init static clkdm dependencies on OMAP5 and + * DRA7 + * + * The dynamic dependency between MPUSS -> EMIF is broken and has + * not worked as expected. The hardware recommendation is to + * enable static dependencies for these to avoid system + * lock ups or random crashes. + */ +static inline int omap5_dra7_init_static_deps(void) +{ + struct clockdomain *mpuss_clkdm, *emif_clkdm; + int ret; + + mpuss_clkdm = clkdm_lookup("mpu_clkdm"); + emif_clkdm = clkdm_lookup("emif_clkdm"); + if (!mpuss_clkdm || !emif_clkdm) + return -EINVAL; + + ret = clkdm_add_wkdep(mpuss_clkdm, emif_clkdm); + if (ret) + pr_err("Failed to add MPUSS -> EMIF wakeup dependency\n"); + + return ret; +} + +/** * omap4_pm_init_early - Does early initialization necessary for OMAP4+ devices * * Initializes basic stuff for power management functionality. @@ -239,10 +265,14 @@ int __init omap4_pm_init(void) goto err2; } - if (cpu_is_omap44xx()) { + if (cpu_is_omap44xx()) ret = omap4_init_static_deps(); - if (ret) - goto err2; + else if (soc_is_omap54xx() || soc_is_dra7xx()) + ret = omap5_dra7_init_static_deps(); + + if (ret) { + pr_err("Failed to initialise static dependencies.\n"); + goto err2; } ret = omap4_mpuss_init(); -- 1.7.9.5