| Message ID | 20171209003414.17332-1-colin.king@canonical.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
Colin, You are right. That's checking is redundant. secs is never be negative. Thanks for your correction and patch. Regards, Ching 2017-12-09 8:34 GMT+08:00 Colin King <colin.king@canonical.com>: > From: Colin Ian King <colin.king@canonical.com> > > The check for secs being less than zero is redundant for two reasons. > Firstly, secs is unsigned so the check is always going to be false. > Secondly, if secs was signed the proceeding calculation of secs is > never going to be negative. Hence we can remove this redundant check > and day and secs re-adjustment. > > Detected by static analysis with smatch: > arcmsr_set_iop_datetime() warn: unsigned 'secs' is never less than zero. > > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > drivers/scsi/arcmsr/arcmsr_hba.c | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c > index 0707a60bf5c0..e4258b69f4be 100644 > --- a/drivers/scsi/arcmsr/arcmsr_hba.c > +++ b/drivers/scsi/arcmsr/arcmsr_hba.c > @@ -3679,10 +3679,6 @@ static void arcmsr_set_iop_datetime(struct timer_list *t) > secs = (u32)(tv.tv_sec - (sys_tz.tz_minuteswest * 60)); > days = secs / 86400; > secs = secs - 86400 * days; > - if (secs < 0) { > - days = days - 1; > - secs = secs + 86400; > - } > j = days / 146097; > i = days - 146097 * j; > a = i + 719468; > -- > 2.14.1 >
Colin, > The check for secs being less than zero is redundant for two reasons. > Firstly, secs is unsigned so the check is always going to be false. > Secondly, if secs was signed the proceeding calculation of secs is > never going to be negative. Hence we can remove this redundant check > and day and secs re-adjustment. Applied to 4.16/scsi-queue, thanks!
Am 09.12.2017 01:34, schrieb Colin King: > From: Colin Ian King <colin.king@canonical.com> > > The check for secs being less than zero is redundant for two reasons. > Firstly, secs is unsigned so the check is always going to be false. > Secondly, if secs was signed the proceeding calculation of secs is > never going to be negative. Hence we can remove this redundant check > and day and secs re-adjustment. > > Detected by static analysis with smatch: > arcmsr_set_iop_datetime() warn: unsigned 'secs' is never less than zero. > > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > drivers/scsi/arcmsr/arcmsr_hba.c | 4 ---- > 1 file changed, 4 deletions(-) > > diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c > index 0707a60bf5c0..e4258b69f4be 100644 > --- a/drivers/scsi/arcmsr/arcmsr_hba.c > +++ b/drivers/scsi/arcmsr/arcmsr_hba.c > @@ -3679,10 +3679,6 @@ static void arcmsr_set_iop_datetime(struct timer_list *t) > secs = (u32)(tv.tv_sec - (sys_tz.tz_minuteswest * 60)); > days = secs / 86400; > secs = secs - 86400 * days; mmh, what they want to do is: secs = secs % 86400 ; > - if (secs < 0) { > - days = days - 1; > - secs = secs + 86400; > - } > j = days / 146097; > i = days - 146097 * j; > a = i + 719468; see above. btw: are the numbers documented ? re, wh
diff --git a/drivers/scsi/arcmsr/arcmsr_hba.c b/drivers/scsi/arcmsr/arcmsr_hba.c index 0707a60bf5c0..e4258b69f4be 100644 --- a/drivers/scsi/arcmsr/arcmsr_hba.c +++ b/drivers/scsi/arcmsr/arcmsr_hba.c @@ -3679,10 +3679,6 @@ static void arcmsr_set_iop_datetime(struct timer_list *t) secs = (u32)(tv.tv_sec - (sys_tz.tz_minuteswest * 60)); days = secs / 86400; secs = secs - 86400 * days; - if (secs < 0) { - days = days - 1; - secs = secs + 86400; - } j = days / 146097; i = days - 146097 * j; a = i + 719468;