[Skiboot] [PATCH] SLW: Remove stop1_lite and stop2_lite

[Akshay Adiga]

On Thu, May 10, 2018 at 02:15:57PM +0530, Akshay Adiga wrote:
> Lite states don't give up the SMT resources, can potentially have a
> performance impact on sibling threads. At latencies of stop1_lite and
> stop2_lite , lite states dont make sense and can have performance
> impact.
> 
> Signed-off-by: Akshay Adiga <akshay.adiga at linux.vnet.ibm.com>
> ---
>  hw/slw.c | 29 +----------------------------
>  1 file changed, 1 insertion(+), 28 deletions(-)
> 
> diff --git a/hw/slw.c b/hw/slw.c
> index c059d9c..513be7b 100644
> --- a/hw/slw.c
> +++ b/hw/slw.c
> @@ -529,20 +529,7 @@ static struct cpu_idle_states power9_cpu_idle_states[] = {
>  				 | OPAL_PM_PSSCR_ESL \
>  				 | OPAL_PM_PSSCR_EC,
>  		.pm_ctrl_reg_mask = OPAL_PM_PSSCR_MASK },
> -	{
> -		.name = "stop1_lite", /* Enter stop1 with no state loss */
> -		.latency_ns = 4900,
> -		.residency_ns = 49000,
> -		.flags = 0*OPAL_PM_DEC_STOP \
> -		       | 0*OPAL_PM_TIMEBASE_STOP  \
> -		       | 0*OPAL_PM_LOSE_USER_CONTEXT \
> -		       | 0*OPAL_PM_LOSE_HYP_CONTEXT \
> -		       | 0*OPAL_PM_LOSE_FULL_CONTEXT \
> -		       | 1*OPAL_PM_STOP_INST_FAST,
> -		.pm_ctrl_reg_val = OPAL_PM_PSSCR_RL(1) \
> -				 | OPAL_PM_PSSCR_MTL(3) \
> -				 | OPAL_PM_PSSCR_TR(3),
> -		.pm_ctrl_reg_mask = OPAL_PM_PSSCR_MASK },
> +
>  	{
>  		.name = "stop1",
>  		.latency_ns = 5000,
> @@ -560,20 +547,6 @@ static struct cpu_idle_states power9_cpu_idle_states[] = {
>  				 | OPAL_PM_PSSCR_EC,
>  		.pm_ctrl_reg_mask = OPAL_PM_PSSCR_MASK },
>  	{
> -		.name = "stop2_lite", /* Enter stop2 with no state loss */
> -		.latency_ns = 9900,
> -		.residency_ns = 99000,
> -		.flags = 0*OPAL_PM_DEC_STOP \
> -		       | 0*OPAL_PM_TIMEBASE_STOP  \
> -		       | 0*OPAL_PM_LOSE_USER_CONTEXT \
> -		       | 0*OPAL_PM_LOSE_HYP_CONTEXT \
> -		       | 0*OPAL_PM_LOSE_FULL_CONTEXT \
> -		       | 1*OPAL_PM_STOP_INST_FAST,
> -		.pm_ctrl_reg_val = OPAL_PM_PSSCR_RL(2) \
> -				 | OPAL_PM_PSSCR_MTL(3) \
> -				 | OPAL_PM_PSSCR_TR(3),
> -		.pm_ctrl_reg_mask = OPAL_PM_PSSCR_MASK },
> -	{
>  		.name = "stop2",
>  		.latency_ns = 10000,
>  		.residency_ns = 100000,
> -- 
> 2.5.5
> 

This is a followup on the previous patch  : https://patchwork.ozlabs.org/patch/906582/ 

Nick,Stewart does this look good ?