* [PATCH][next] tty: serial: jsm: remove redundant assignments of several variables
@ 2021-04-22 12:11 Colin King
2021-04-22 12:52 ` Johan Hovold
0 siblings, 1 reply; 6+ messages in thread
From: Colin King @ 2021-04-22 12:11 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby, Lee Jones, linux-serial
Cc: kernel-janitors, linux-kernel
From: Colin Ian King <colin.king@canonical.com>
Several variables are being assigned with values that are never
read and being updated later with a new value. The initializations
are redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
drivers/tty/serial/jsm/jsm_cls.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/jsm/jsm_cls.c b/drivers/tty/serial/jsm/jsm_cls.c
index b507a2cec926..b58ea4344aaf 100644
--- a/drivers/tty/serial/jsm/jsm_cls.c
+++ b/drivers/tty/serial/jsm/jsm_cls.c
@@ -349,8 +349,8 @@ static void cls_assert_modem_signals(struct jsm_channel *ch)
static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch)
{
- int qleft = 0;
- u8 linestatus = 0;
+ int qleft;
+ u8 linestatus;
u8 error_mask = 0;
u16 head;
u16 tail;
@@ -365,8 +365,6 @@ static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch)
head = ch->ch_r_head & RQUEUEMASK;
tail = ch->ch_r_tail & RQUEUEMASK;
- /* Get our cached LSR */
- linestatus = ch->ch_cached_lsr;
ch->ch_cached_lsr = 0;
/* Store how much space we have left in the queue */
--
2.30.2
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH][next] tty: serial: jsm: remove redundant assignments of several variables 2021-04-22 12:11 [PATCH][next] tty: serial: jsm: remove redundant assignments of several variables Colin King @ 2021-04-22 12:52 ` Johan Hovold 2021-04-22 12:53 ` Colin Ian King 0 siblings, 1 reply; 6+ messages in thread From: Johan Hovold @ 2021-04-22 12:52 UTC (permalink / raw) To: Colin King Cc: Greg Kroah-Hartman, Jiri Slaby, Lee Jones, linux-serial, kernel-janitors, linux-kernel On Thu, Apr 22, 2021 at 01:11:15PM +0100, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > Several variables are being assigned with values that are never > read and being updated later with a new value. The initializations > are redundant and can be removed. > > Addresses-Coverity: ("Unused value") > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > drivers/tty/serial/jsm/jsm_cls.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/drivers/tty/serial/jsm/jsm_cls.c b/drivers/tty/serial/jsm/jsm_cls.c > index b507a2cec926..b58ea4344aaf 100644 > --- a/drivers/tty/serial/jsm/jsm_cls.c > +++ b/drivers/tty/serial/jsm/jsm_cls.c > @@ -349,8 +349,8 @@ static void cls_assert_modem_signals(struct jsm_channel *ch) > > static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch) > { > - int qleft = 0; > - u8 linestatus = 0; > + int qleft; > + u8 linestatus; > u8 error_mask = 0; > u16 head; > u16 tail; > @@ -365,8 +365,6 @@ static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch) > head = ch->ch_r_head & RQUEUEMASK; > tail = ch->ch_r_tail & RQUEUEMASK; > > - /* Get our cached LSR */ > - linestatus = ch->ch_cached_lsr; > ch->ch_cached_lsr = 0; Why leave this assignment in? Looks like this was all copy-pasta, but this assignment makes even less sense now that you remove the comment and load. Johan ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][next] tty: serial: jsm: remove redundant assignments of several variables 2021-04-22 12:52 ` Johan Hovold @ 2021-04-22 12:53 ` Colin Ian King 2021-04-22 12:56 ` Johan Hovold 0 siblings, 1 reply; 6+ messages in thread From: Colin Ian King @ 2021-04-22 12:53 UTC (permalink / raw) To: Johan Hovold Cc: Greg Kroah-Hartman, Jiri Slaby, Lee Jones, linux-serial, kernel-janitors, linux-kernel On 22/04/2021 13:52, Johan Hovold wrote: > On Thu, Apr 22, 2021 at 01:11:15PM +0100, Colin King wrote: >> From: Colin Ian King <colin.king@canonical.com> >> >> Several variables are being assigned with values that are never >> read and being updated later with a new value. The initializations >> are redundant and can be removed. >> >> Addresses-Coverity: ("Unused value") >> Signed-off-by: Colin Ian King <colin.king@canonical.com> >> --- >> drivers/tty/serial/jsm/jsm_cls.c | 6 ++---- >> 1 file changed, 2 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/tty/serial/jsm/jsm_cls.c b/drivers/tty/serial/jsm/jsm_cls.c >> index b507a2cec926..b58ea4344aaf 100644 >> --- a/drivers/tty/serial/jsm/jsm_cls.c >> +++ b/drivers/tty/serial/jsm/jsm_cls.c >> @@ -349,8 +349,8 @@ static void cls_assert_modem_signals(struct jsm_channel *ch) >> >> static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch) >> { >> - int qleft = 0; >> - u8 linestatus = 0; >> + int qleft; >> + u8 linestatus; >> u8 error_mask = 0; >> u16 head; >> u16 tail; >> @@ -365,8 +365,6 @@ static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch) >> head = ch->ch_r_head & RQUEUEMASK; >> tail = ch->ch_r_tail & RQUEUEMASK; >> >> - /* Get our cached LSR */ >> - linestatus = ch->ch_cached_lsr; >> ch->ch_cached_lsr = 0; > > Why leave this assignment in? Looks like this was all copy-pasta, but > this assignment makes even less sense now that you remove the comment > and load. Which assignment are you referring to? > > Johan > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][next] tty: serial: jsm: remove redundant assignments of several variables 2021-04-22 12:53 ` Colin Ian King @ 2021-04-22 12:56 ` Johan Hovold 2021-04-22 13:01 ` Colin Ian King 0 siblings, 1 reply; 6+ messages in thread From: Johan Hovold @ 2021-04-22 12:56 UTC (permalink / raw) To: Colin Ian King Cc: Greg Kroah-Hartman, Jiri Slaby, Lee Jones, linux-serial, kernel-janitors, linux-kernel On Thu, Apr 22, 2021 at 01:53:03PM +0100, Colin Ian King wrote: > On 22/04/2021 13:52, Johan Hovold wrote: > > On Thu, Apr 22, 2021 at 01:11:15PM +0100, Colin King wrote: > >> From: Colin Ian King <colin.king@canonical.com> > >> > >> Several variables are being assigned with values that are never > >> read and being updated later with a new value. The initializations > >> are redundant and can be removed. > >> > >> Addresses-Coverity: ("Unused value") > >> Signed-off-by: Colin Ian King <colin.king@canonical.com> > >> --- > >> drivers/tty/serial/jsm/jsm_cls.c | 6 ++---- > >> 1 file changed, 2 insertions(+), 4 deletions(-) > >> > >> diff --git a/drivers/tty/serial/jsm/jsm_cls.c b/drivers/tty/serial/jsm/jsm_cls.c > >> index b507a2cec926..b58ea4344aaf 100644 > >> --- a/drivers/tty/serial/jsm/jsm_cls.c > >> +++ b/drivers/tty/serial/jsm/jsm_cls.c > >> @@ -349,8 +349,8 @@ static void cls_assert_modem_signals(struct jsm_channel *ch) > >> > >> static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch) > >> { > >> - int qleft = 0; > >> - u8 linestatus = 0; > >> + int qleft; > >> + u8 linestatus; > >> u8 error_mask = 0; > >> u16 head; > >> u16 tail; > >> @@ -365,8 +365,6 @@ static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch) > >> head = ch->ch_r_head & RQUEUEMASK; > >> tail = ch->ch_r_tail & RQUEUEMASK; > >> > >> - /* Get our cached LSR */ > >> - linestatus = ch->ch_cached_lsr; > >> ch->ch_cached_lsr = 0; > > > > Why leave this assignment in? Looks like this was all copy-pasta, but > > this assignment makes even less sense now that you remove the comment > > and load. > > Which assignment are you referring to? The one just above my comment: ch->ch_cached_lsr = 0; Johan ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][next] tty: serial: jsm: remove redundant assignments of several variables 2021-04-22 12:56 ` Johan Hovold @ 2021-04-22 13:01 ` Colin Ian King 2021-04-22 13:15 ` Johan Hovold 0 siblings, 1 reply; 6+ messages in thread From: Colin Ian King @ 2021-04-22 13:01 UTC (permalink / raw) To: Johan Hovold Cc: Greg Kroah-Hartman, Jiri Slaby, Lee Jones, linux-serial, kernel-janitors, linux-kernel On 22/04/2021 13:56, Johan Hovold wrote: > On Thu, Apr 22, 2021 at 01:53:03PM +0100, Colin Ian King wrote: >> On 22/04/2021 13:52, Johan Hovold wrote: >>> On Thu, Apr 22, 2021 at 01:11:15PM +0100, Colin King wrote: >>>> From: Colin Ian King <colin.king@canonical.com> >>>> >>>> Several variables are being assigned with values that are never >>>> read and being updated later with a new value. The initializations >>>> are redundant and can be removed. >>>> >>>> Addresses-Coverity: ("Unused value") >>>> Signed-off-by: Colin Ian King <colin.king@canonical.com> >>>> --- >>>> drivers/tty/serial/jsm/jsm_cls.c | 6 ++---- >>>> 1 file changed, 2 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/drivers/tty/serial/jsm/jsm_cls.c b/drivers/tty/serial/jsm/jsm_cls.c >>>> index b507a2cec926..b58ea4344aaf 100644 >>>> --- a/drivers/tty/serial/jsm/jsm_cls.c >>>> +++ b/drivers/tty/serial/jsm/jsm_cls.c >>>> @@ -349,8 +349,8 @@ static void cls_assert_modem_signals(struct jsm_channel *ch) >>>> >>>> static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch) >>>> { >>>> - int qleft = 0; >>>> - u8 linestatus = 0; >>>> + int qleft; >>>> + u8 linestatus; >>>> u8 error_mask = 0; >>>> u16 head; >>>> u16 tail; >>>> @@ -365,8 +365,6 @@ static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch) >>>> head = ch->ch_r_head & RQUEUEMASK; >>>> tail = ch->ch_r_tail & RQUEUEMASK; >>>> >>>> - /* Get our cached LSR */ >>>> - linestatus = ch->ch_cached_lsr; >>>> ch->ch_cached_lsr = 0; >>> >>> Why leave this assignment in? Looks like this was all copy-pasta, but >>> this assignment makes even less sense now that you remove the comment >>> and load. >> >> Which assignment are you referring to? > > The one just above my comment: > > ch->ch_cached_lsr = 0; that cached value is being used in jsm_neo.c, so removing the zero'ing may cause some issues. > > Johan > ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH][next] tty: serial: jsm: remove redundant assignments of several variables 2021-04-22 13:01 ` Colin Ian King @ 2021-04-22 13:15 ` Johan Hovold 0 siblings, 0 replies; 6+ messages in thread From: Johan Hovold @ 2021-04-22 13:15 UTC (permalink / raw) To: Colin Ian King Cc: Greg Kroah-Hartman, Jiri Slaby, Lee Jones, linux-serial, kernel-janitors, linux-kernel On Thu, Apr 22, 2021 at 02:01:36PM +0100, Colin Ian King wrote: > On 22/04/2021 13:56, Johan Hovold wrote: > > On Thu, Apr 22, 2021 at 01:53:03PM +0100, Colin Ian King wrote: > >> On 22/04/2021 13:52, Johan Hovold wrote: > >>> On Thu, Apr 22, 2021 at 01:11:15PM +0100, Colin King wrote: > >>>> From: Colin Ian King <colin.king@canonical.com> > >>>> > >>>> Several variables are being assigned with values that are never > >>>> read and being updated later with a new value. The initializations > >>>> are redundant and can be removed. > >>>> > >>>> Addresses-Coverity: ("Unused value") > >>>> Signed-off-by: Colin Ian King <colin.king@canonical.com> > >>>> --- > >>>> drivers/tty/serial/jsm/jsm_cls.c | 6 ++---- > >>>> 1 file changed, 2 insertions(+), 4 deletions(-) > >>>> > >>>> diff --git a/drivers/tty/serial/jsm/jsm_cls.c b/drivers/tty/serial/jsm/jsm_cls.c > >>>> index b507a2cec926..b58ea4344aaf 100644 > >>>> --- a/drivers/tty/serial/jsm/jsm_cls.c > >>>> +++ b/drivers/tty/serial/jsm/jsm_cls.c > >>>> @@ -349,8 +349,8 @@ static void cls_assert_modem_signals(struct jsm_channel *ch) > >>>> > >>>> static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch) > >>>> { > >>>> - int qleft = 0; > >>>> - u8 linestatus = 0; > >>>> + int qleft; > >>>> + u8 linestatus; > >>>> u8 error_mask = 0; > >>>> u16 head; > >>>> u16 tail; > >>>> @@ -365,8 +365,6 @@ static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch) > >>>> head = ch->ch_r_head & RQUEUEMASK; > >>>> tail = ch->ch_r_tail & RQUEUEMASK; > >>>> > >>>> - /* Get our cached LSR */ > >>>> - linestatus = ch->ch_cached_lsr; > >>>> ch->ch_cached_lsr = 0; > >>> > >>> Why leave this assignment in? Looks like this was all copy-pasta, but > >>> this assignment makes even less sense now that you remove the comment > >>> and load. > >> > >> Which assignment are you referring to? > > > > The one just above my comment: > > > > ch->ch_cached_lsr = 0; > > that cached value is being used in jsm_neo.c, so removing the zero'ing > may cause some issues. That's for you to determine, right? Only doing half of a clean may actually be worse than doing nothing at all. At least now it's somewhat clear why that statement is there. The jsm_neo.c implements support for a different class of devices and only those actually use ch_cached_lsr AFAICT. It would be good if you include some context in the commit message such as which commit added this code and that it has never been used. Johan ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-04-22 13:15 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-04-22 12:11 [PATCH][next] tty: serial: jsm: remove redundant assignments of several variables Colin King 2021-04-22 12:52 ` Johan Hovold 2021-04-22 12:53 ` Colin Ian King 2021-04-22 12:56 ` Johan Hovold 2021-04-22 13:01 ` Colin Ian King 2021-04-22 13:15 ` Johan Hovold
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