Re: [PATCH v4] powerpc/pseries: make max polling consistent for longer H_CALLs

[Andrew Donnellan <ajd@linux.ibm.com>]

On Wed, 2024-04-17 at 23:12 -0400, Nayna Jain wrote:
> Currently, plpks_confirm_object_flushed() function polls for 5msec in
> total instead of 5sec.
> 
> Keep max polling time consistent for all the H_CALLs, which take
> longer
> than expected, to be 5sec. Also, make use of fsleep() everywhere to
> insert delay.
> 
> Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
> Fixes: 2454a7af0f2a ("powerpc/pseries: define driver for Platform
> KeyStore")
> Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
> Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>

Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>

> ---
> v4:
>  * As per Andrew's feedback, squashed Patch 2 with Patch 1.
> Now it is single patch.
> 
> v3:
>  * Addition to Patch 1 timeout patch based on Andrew's feedback.
> 
> v2:
> * Updated based on feedback from Michael Ellerman
>         Replaced usleep_range with fsleep.
>         Since there is no more need to specify range, sleep time is
> reverted back to 10 msec.
> 
>  arch/powerpc/include/asm/plpks.h       |  5 ++---
>  arch/powerpc/platforms/pseries/plpks.c | 10 +++++-----
>  2 files changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/plpks.h
> b/arch/powerpc/include/asm/plpks.h
> index 23b77027c916..7a84069759b0 100644
> --- a/arch/powerpc/include/asm/plpks.h
> +++ b/arch/powerpc/include/asm/plpks.h
> @@ -44,9 +44,8 @@
>  #define PLPKS_MAX_DATA_SIZE		4000
>  
>  // Timeouts for PLPKS operations
> -#define PLPKS_MAX_TIMEOUT		5000 // msec
> -#define PLPKS_FLUSH_SLEEP		10 // msec
> -#define PLPKS_FLUSH_SLEEP_RANGE		400
> +#define PLPKS_MAX_TIMEOUT		(5 * USEC_PER_SEC)
> +#define PLPKS_FLUSH_SLEEP		10000 // usec
>  
>  struct plpks_var {
>  	char *component;
> diff --git a/arch/powerpc/platforms/pseries/plpks.c
> b/arch/powerpc/platforms/pseries/plpks.c
> index febe18f251d0..4a595493d28a 100644
> --- a/arch/powerpc/platforms/pseries/plpks.c
> +++ b/arch/powerpc/platforms/pseries/plpks.c
> @@ -415,8 +415,7 @@ static int plpks_confirm_object_flushed(struct
> label *label,
>  			break;
>  		}
>  
> -		usleep_range(PLPKS_FLUSH_SLEEP,
> -			     PLPKS_FLUSH_SLEEP +
> PLPKS_FLUSH_SLEEP_RANGE);
> +		fsleep(PLPKS_FLUSH_SLEEP);
>  		timeout = timeout + PLPKS_FLUSH_SLEEP;
>  	} while (timeout < PLPKS_MAX_TIMEOUT);
>  
> @@ -464,9 +463,10 @@ int plpks_signed_update_var(struct plpks_var
> *var, u64 flags)
>  
>  		continuetoken = retbuf[0];
>  		if (pseries_status_to_err(rc) == -EBUSY) {
> -			int delay_ms = get_longbusy_msecs(rc);
> -			mdelay(delay_ms);
> -			timeout += delay_ms;
> +			int delay_us = get_longbusy_msecs(rc) *
> 1000;
> +
> +			fsleep(delay_us);
> +			timeout += delay_us;
>  		}
>  		rc = pseries_status_to_err(rc);
>  	} while (rc == -EBUSY && timeout < PLPKS_MAX_TIMEOUT);

-- 
Andrew Donnellan    OzLabs, ADL Canberra
ajd@linux.ibm.com   IBM Australia Limited