Discussion:
[PATCH v2] scsi: ips.c: Use jiffies comparison instead of do_gettimeofday()
(too old to reply)
Ebru Akagunduz
2014-10-20 17:06:01 UTC
Permalink
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 <***@gmail.com>
---
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*/
--
1.9.1
James Bottomley
2014-10-20 17:39:48 UTC
Permalink
Post by Ebru Akagunduz
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.
---
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
Arnd Bergmann
2014-10-20 17:43:18 UTC
Permalink
Post by Ebru Akagunduz
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.
The description doesn't seem to match what you are doing:

- the use of 'struct timeval' in this driver is not actually unsafe
- using jiffies does not make it use a 64-bit time type.
- you do not mention that using jiffies makes the driver more
efficient, which is what James was interested in
- The ips_fix_ffdc_time that needs to be changed for 64-bit time
does not get changed in this patch. As discussed on IRC, that
should be a separate patch.
Post by Ebru Akagunduz
@@ -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;
Using 'unsigned long' for a jiffies value also breaks the function, which
makes calculations based on the assumption that you are dealing with a
time_t. I think the best fix here is to use rtc_ktime_to_tm(ktime_get())
to get a 'struct rtc_time' describing the current time, and then removing
most of the code.

You will have to change Kconfig to 'select RTC_LIB' from the ips driver
in order to do this.

Arnd

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