Re: [PATCH v2] scsi: ips.c: Use jiffies comparison instead of do_gettimeofday()

From: James Bottomley
Date: Mon Oct 20 2014 - 13:40:11 EST


On Mon, 2014-10-20 at 20:06 +0300, Ebru Akagunduz wrote:
> do_gettimeofday() only can get 32-bit time types
> but the driver should be able to use dates that are
> after January 2038.
>
> Remove do_gettimeofday() and use
> jiffies comparison to supply 64-bit time types.
>
> Signed-off-by: Ebru Akagunduz <ebru.akagunduz@xxxxxxxxx>
> ---
> drivers/scsi/ips.c | 25 +++++++++++++------------
> drivers/scsi/ips.h | 2 +-
> 2 files changed, 14 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/scsi/ips.c b/drivers/scsi/ips.c
> index e5afc38..6d27024 100644
> --- a/drivers/scsi/ips.c
> +++ b/drivers/scsi/ips.c
> @@ -162,6 +162,7 @@
> */
>
> #include <asm/io.h>
> +#include <linux/jiffies.h>
> #include <asm/byteorder.h>
> #include <asm/page.h>
> #include <linux/stddef.h>
> @@ -297,7 +298,7 @@ static void ips_freescb(ips_ha_t *, ips_scb_t *);
> static void ips_setup_funclist(ips_ha_t *);
> static void ips_statinit(ips_ha_t *);
> static void ips_statinit_memio(ips_ha_t *);
> -static void ips_fix_ffdc_time(ips_ha_t *, ips_scb_t *, time_t);
> +static void ips_fix_ffdc_time(ips_ha_t *, ips_scb_t *, unsigned long);
> static void ips_ffdc_reset(ips_ha_t *, int);
> static void ips_ffdc_time(ips_ha_t *);
> static uint32_t ips_statupd_copperhead(ips_ha_t *);
> @@ -993,10 +994,10 @@ static int __ips_eh_reset(struct scsi_cmnd *SC)
>
> /* FFDC */
> if (le32_to_cpu(ha->subsys->param[3]) & 0x300000) {
> - struct timeval tv;
> + unsigned long now;
>
> - do_gettimeofday(&tv);
> - ha->last_ffdc = tv.tv_sec;
> + now = jiffies;
> + ha->last_ffdc = jiffies;
> ha->reset_count++;
> ips_ffdc_reset(ha, IPS_INTR_IORL);
> }
> @@ -2404,7 +2405,7 @@ static int
> ips_hainit(ips_ha_t * ha)
> {
> int i;
> - struct timeval tv;
> + unsigned long now;
>
> METHOD_TRACE("ips_hainit", 1);
>
> @@ -2419,8 +2420,8 @@ ips_hainit(ips_ha_t * ha)
>
> /* Send FFDC */
> ha->reset_count = 1;
> - do_gettimeofday(&tv);
> - ha->last_ffdc = tv.tv_sec;
> + now = jiffies;
> + ha->last_ffdc = jiffies;
> ips_ffdc_reset(ha, IPS_INTR_IORL);
>
> if (!ips_read_config(ha, IPS_INTR_IORL)) {
> @@ -2560,12 +2561,12 @@ ips_next(ips_ha_t * ha, int intr)
>
> if ((ha->subsys->param[3] & 0x300000)
> && (ha->scb_activelist.count == 0)) {
> - struct timeval tv;
> + unsigned long now;
>
> - do_gettimeofday(&tv);
> + now = jiffies;
>
> - if (tv.tv_sec - ha->last_ffdc > IPS_SECS_8HOURS) {
> - ha->last_ffdc = tv.tv_sec;
> + if (time_after(now, ha->last_ffdc + IPS_SECS_8HOURS * HZ)) {
> + ha->last_ffdc = now;
> ips_ffdc_time(ha);
> }
> }
> @@ -6000,7 +6001,7 @@ ips_ffdc_time(ips_ha_t * ha)
> /* */
> /****************************************************************************/
> static void
> -ips_fix_ffdc_time(ips_ha_t * ha, ips_scb_t * scb, time_t current_time)
> +ips_fix_ffdc_time(ips_ha_t * ha, ips_scb_t * scb, unsigned long current_time)
> {
> long days;
> long rem;
> diff --git a/drivers/scsi/ips.h b/drivers/scsi/ips.h
> index 45b9566..250beea 100644
> --- a/drivers/scsi/ips.h
> +++ b/drivers/scsi/ips.h
> @@ -1054,7 +1054,7 @@ typedef struct ips_ha {
> uint8_t active;
> int ioctl_reset; /* IOCTL Requested Reset Flag */
> uint16_t reset_count; /* number of resets */
> - time_t last_ffdc; /* last time we sent ffdc info*/
> + unsigned long last_ffdc; /* last time we sent ffdc info*/
> uint8_t slot_num; /* PCI Slot Number */
> int ioctl_len; /* size of ioctl buffer */
> dma_addr_t ioctl_busaddr; /* dma address of ioctl buffer*/

Great, looks exactly correct as far as it goes, but without the second
part (converting ips_fix_ffdc_time() to use 64 bit time) it won't
actually work. The problem is jiffies is a relative time measurement
and the RAID engine needs its real time clock setting periodically, so
there's no need to pass current_time (which is no longer current_time)
into ips_fix_ffdc_time(); just have that routine get the 64 bit time and
convert it to the format the card wants.

James


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