From mboxrd@z Thu Jan 1 00:00:00 1970 From: santosh.shilimkar@ti.com (Santosh Shilimkar) Date: Fri, 1 Mar 2013 17:40:53 +0530 Subject: [PATCH 04/15] ARM: OMAP5: PM: Set MPUSS-EMIF clock-domain static dependency In-Reply-To: <1362139864-9233-1-git-send-email-santosh.shilimkar@ti.com> References: <1362139864-9233-1-git-send-email-santosh.shilimkar@ti.com> Message-ID: <1362139864-9233-5-git-send-email-santosh.shilimkar@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Signed-off-by: Santosh Shilimkar --- arch/arm/mach-omap2/pm_omap4plus.c | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) diff --git a/arch/arm/mach-omap2/pm_omap4plus.c b/arch/arm/mach-omap2/pm_omap4plus.c index 95d2712..4c37c47 100644 --- a/arch/arm/mach-omap2/pm_omap4plus.c +++ b/arch/arm/mach-omap2/pm_omap4plus.c @@ -168,6 +168,32 @@ static inline int omap4_init_static_deps(void) } /** + * omap5_init_static_deps - Init static clkdm dependencies on OMAP5 + * + * 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_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 - Init routine for OMAP4+ devices * * Initializes all powerdomain and clockdomain target states @@ -190,10 +216,14 @@ 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()) + ret = omap5_init_static_deps(); + + if (ret) { + pr_err("Failed to initialise static dependencies.\n"); + goto err2; } ret = omap4_mpuss_init(); -- 1.7.9.5