[PATCH 1/8] ARM: OMAP2+: PM: protect the power domain state change by a mutex
From: Rajendra Nayak <hidden>
Date: 2012-06-20 09:17:33
Also in:
linux-omap
On Thursday 14 June 2012 08:23 PM, Jean Pihet wrote:
omap_set_pwrdm_state is intented to be the only API for changing a power domain state.
Yes, but there are others which are used to _read_ the power domain state. Shouldn't those be protected too?
quoted hunk ↗ jump to hunk
This patch protects the power domains settings and structs from concurrent accesses to the function by using a mutex. Signed-off-by: Jean Pihet<redacted> --- arch/arm/mach-omap2/pm.c | 8 ++++++-- arch/arm/mach-omap2/powerdomain.c | 1 + arch/arm/mach-omap2/powerdomain.h | 3 ++- 3 files changed, 9 insertions(+), 3 deletions(-)diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c index 9cb5ced..a05f00c 100644 --- a/arch/arm/mach-omap2/pm.c +++ b/arch/arm/mach-omap2/pm.c@@ -100,15 +100,17 @@ int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 pwrst) if (!pwrdm || IS_ERR(pwrdm)) return -EINVAL; + mutex_lock(&pwrdm->lock); + while (!(pwrdm->pwrsts& (1<< pwrst))) { if (pwrst == PWRDM_POWER_OFF) - return ret; + goto out; pwrst--; } next_pwrst = pwrdm_read_next_pwrst(pwrdm); if (next_pwrst == pwrst) - return ret; + goto out; curr_pwrst = pwrdm_read_pwrst(pwrdm); if (curr_pwrst< PWRDM_POWER_ON) {@@ -141,6 +143,8 @@ int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 pwrst) break; } +out: + mutex_unlock(&pwrdm->lock); return ret; }diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c index 9611490..1641e72 100644 --- a/arch/arm/mach-omap2/powerdomain.c +++ b/arch/arm/mach-omap2/powerdomain.c@@ -102,6 +102,7 @@ static int _pwrdm_register(struct powerdomain *pwrdm) INIT_LIST_HEAD(&pwrdm->voltdm_node); voltdm_add_pwrdm(voltdm, pwrdm); + mutex_init(&pwrdm->lock); list_add(&pwrdm->node,&pwrdm_list); /* Initialize the powerdomain's state counter */diff --git a/arch/arm/mach-omap2/powerdomain.h b/arch/arm/mach-omap2/powerdomain.h index 8f88d65..bab84fc 100644 --- a/arch/arm/mach-omap2/powerdomain.h +++ b/arch/arm/mach-omap2/powerdomain.h@@ -19,7 +19,7 @@ #include<linux/types.h> #include<linux/list.h> - +#include<linux/mutex.h> #include<linux/atomic.h> #include<plat/cpu.h>@@ -116,6 +116,7 @@ struct powerdomain { struct clockdomain *pwrdm_clkdms[PWRDM_MAX_CLKDMS]; struct list_head node; struct list_head voltdm_node; + struct mutex lock; int state; unsigned state_counter[PWRDM_MAX_PWRSTS]; unsigned ret_logic_off_counter;