Re: [PATCH 2/3] scsi: 3ware: use 64-bit times for FW time sync

adam radford
2017-11-10T19:43:44Z

On Fri, Nov 10, 2017 at 7:58 AM, Arnd Bergmann <arnd@arndb.de> wrote:
> The calculation of the number of seconds since Sunday 00:00:00 overflows
> in 2106, meaning that we instead will return the seconds since Wednesday
> 06:28:16 afterwards.
>
> Using 64-bit time stamps avoids this slight inconsistency, and the
> deprecated do_gettimeofday(), replacing it with the simpler
> ktime_get_real_seconds().
>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> drivers/scsi/3w-9xxx.c | 8 +++-----
> drivers/scsi/3w-sas.c | 10 ++++------
> 2 files changed, 7 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
> index cb9af3f7b653..b1c9bd9c1bfd 100644
> --- a/drivers/scsi/3w-9xxx.c
> +++ b/drivers/scsi/3w-9xxx.c
> @@ -472,11 +472,10 @@ static char *twa_aen_severity_lookup(unsigned char severity_code)
> static void twa_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
> {
> u32 schedulertime;
> - struct timeval utc;
> TW_Command_Full *full_command_packet;
> TW_Command *command_packet;
> TW_Param_Apache *param;
> - u32 local_time;
> + time64_t local_time;
>
> /* Fill out the command packet */
> full_command_packet = tw_dev->command_packet_virt[request_id];
> @@ -498,9 +497,8 @@ static void twa_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
>
> /* Convert system time in UTC to local time seconds since last
> Sunday 12:00AM */
> - do_gettimeofday(&utc);
> - local_time = (u32)(utc.tv_sec - (sys_tz.tz_minuteswest * 60));
> - schedulertime = local_time - (3 * 86400);
> + local_time = (ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
> + div_u64_rem(local_time - (3 * 86400), 604800, &schedulertime);
> schedulertime = cpu_to_le32(schedulertime % 604800);
>
> memcpy(param->data, &schedulertime, sizeof(u32));
> diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
> index c283fdb3cb24..cf9f2a09b47d 100644
> --- a/drivers/scsi/3w-sas.c
> +++ b/drivers/scsi/3w-sas.c
> @@ -407,11 +407,10 @@ static int twl_aen_read_queue(TW_Device_Extension *tw_dev, int request_id)
> static void twl_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
> {
> u32 schedulertime;
> - struct timeval utc;
> TW_Command_Full *full_command_packet;
> TW_Command *command_packet;
> TW_Param_Apache *param;
> - u32 local_time;
> + time64_t local_time;
>
> /* Fill out the command packet */
> full_command_packet = tw_dev->command_packet_virt[request_id];
> @@ -433,10 +432,9 @@ static void twl_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
>
> /* Convert system time in UTC to local time seconds since last
> Sunday 12:00AM */
> - do_gettimeofday(&utc);
> - local_time = (u32)(utc.tv_sec - (sys_tz.tz_minuteswest * 60));
> - schedulertime = local_time - (3 * 86400);
> - schedulertime = cpu_to_le32(schedulertime % 604800);
> + local_time = (ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
> + div_u64_rem(local_time - (3 * 86400), 604800, &schedulertime);
> + schedulertime = cpu_to_le32(schedulertime);
>
> memcpy(param->data, &schedulertime, sizeof(u32));
>
> --
> 2.9.0
>

Acked-by: Adam Radford <aradford@gmail.com>