On 2013年04月01日 18:25, Paul Walmsley wrote:
> Hi,
>
> On Thu, 14 Mar 2013, Chen Gang wrote:
>
>>
>> if pwrdm_read_pwrst returns negative number, curr_pwrst can not notice it.
>> since really need check curr_pwrst whether is negative,
>> need let the check valid in _pwrdm_save_clkdm_state_and_activate.
>> and also better to check the return value of pwrdm_read_pwrst, firstly.
>>
>> Signed-off-by: Chen Gang <gang.chen@xxxxxxxxxxx>
>
> thanks for reporting this and sending a suggested fix. The following
> patch is what I've queued here, which should deal with the root cause
> without the casts.
>
>
yours (patch below) is simpler and clearer than mine.
thanks.
:-)
> - Paul
>
> From: Paul Walmsley <paul@xxxxxxxxx>
> Date: Sun, 31 Mar 2013 20:22:22 -0600
> Subject: [PATCH] ARM: OMAP2+: powerdomain: avoid testing whether an unsigned
> char is less than 0
>
> _pwrdm_save_clkdm_state_and_activate() tried to test one of its
> unsigned arguments to determine whether it was less than zero. Fix by
> moving the error test to the caller.
>
> Reported-by: Chen Gang <gang.chen@xxxxxxxxxxx>
> Signed-off-by: Paul Walmsley <paul@xxxxxxxxx>
> ---
> arch/arm/mach-omap2/powerdomain.c | 18 ++++++++----------
> 1 file changed, 8 insertions(+), 10 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
> index 8e61d80..89cad4a 100644
> --- a/arch/arm/mach-omap2/powerdomain.c
> +++ b/arch/arm/mach-omap2/powerdomain.c
> @@ -52,7 +52,6 @@ enum {
> #define ALREADYACTIVE_SWITCH 0
> #define FORCEWAKEUP_SWITCH 1
> #define LOWPOWERSTATE_SWITCH 2
> -#define ERROR_SWITCH 3
>
> /* pwrdm_list contains all registered struct powerdomains */
> static LIST_HEAD(pwrdm_list);
> @@ -233,10 +232,7 @@ static u8 _pwrdm_save_clkdm_state_and_activate(struct powerdomain *pwrdm,
> {
> u8 sleep_switch;
>
> - if (curr_pwrst < 0) {
> - WARN_ON(1);
> - sleep_switch = ERROR_SWITCH;
> - } else if (curr_pwrst < PWRDM_POWER_ON) {
> + if (curr_pwrst < PWRDM_POWER_ON) {
> if (curr_pwrst > pwrst &&
> pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE &&
> arch_pwrdm->pwrdm_set_lowpwrstchange) {
> @@ -1091,7 +1087,8 @@ int pwrdm_post_transition(struct powerdomain *pwrdm)
> */
> int omap_set_pwrdm_state(struct powerdomain *pwrdm, u8 pwrst)
> {
> - u8 curr_pwrst, next_pwrst, sleep_switch;
> + u8 next_pwrst, sleep_switch;
> + int curr_pwrst;
> int ret = 0;
> bool hwsup = false;
>
> @@ -1107,16 +1104,17 @@ int omap_set_pwrdm_state(struct powerdomain *pwrdm, u8 pwrst)
> pwrdm_lock(pwrdm);
>
> curr_pwrst = pwrdm_read_pwrst(pwrdm);
> + if (curr_pwrst < 0) {
> + ret = -EINVAL;
> + goto osps_out;
> + }
> +
> next_pwrst = pwrdm_read_next_pwrst(pwrdm);
> if (curr_pwrst == pwrst && next_pwrst == pwrst)
> goto osps_out;
>
> sleep_switch = _pwrdm_save_clkdm_state_and_activate(pwrdm, curr_pwrst,
> pwrst, &hwsup);
> - if (sleep_switch == ERROR_SWITCH) {
> - ret = -EINVAL;
> - goto osps_out;
> - }
>
> ret = pwrdm_set_next_pwrst(pwrdm, pwrst);
> if (ret)
>
--
Chen Gang
Asianux Corporation
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