[PATCH 02/10] ARM: OMAP5 / DRA7: PM: Set MPUSS-EMIF clock-domain static dependency
From: nm@ti.com (Nishanth Menon)
Date: 2014-08-22 14:03:05
Also in:
linux-omap, lkml
Subsystem:
arm port, omap power management support, omap2+ support, the rest · Maintainers:
Russell King, Kevin Hilman, Aaro Koskinen, Andreas Kemnade, Roger Quadros, Tony Lindgren, Linus Torvalds
From: Santosh Shilimkar <redacted> 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 <redacted> [rnayak at ti.com: DRA7] Signed-off-by: Rajendra Nayak <redacted> [nm at ti.com: conflict resolution, dra7] Signed-off-by: Nishanth Menon <nm@ti.com> --- 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