From: Greg KH <gregkh@linuxfoundation.org>
To: YueHaibing <yuehaibing@huawei.com>
Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: [PATCH -next] usb: ftdi-elan: Fix if == else warnings in ftdi_elan_respond_engine
Date: Wed, 23 Jan 2019 14:41:48 +0100 [thread overview]
Message-ID: <20190123134147.GC24700@kroah.com> (raw)
In-Reply-To: <10d0f378-03ab-1855-1476-a39cf6b816ab@huawei.com>
On Wed, Jan 23, 2019 at 09:17:38PM +0800, YueHaibing wrote:
> On 2019/1/23 20:43, Greg KH wrote:
> > On Wed, Jan 23, 2019 at 08:34:42PM +0800, YueHaibing wrote:
> >> ./drivers/usb/misc/ftdi-elan.c:972:10-12: WARNING: possible condition with no effect (if == else)
> >> ./drivers/usb/misc/ftdi-elan.c:983:9-11: WARNING: possible condition with no effect (if == else)
> >> ./drivers/usb/misc/ftdi-elan.c:2052:11-13: WARNING: possible condition with no effect (if == else)
> >>
> >> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
> >
> > You can not just provide the output of a tool as a changelog text,
> > sorry.
> >
> > Please explain what those lines mean, and why you are making the change
> > that you are.
>
> ok, will do that.
>
> >
> >> ---
> >> drivers/usb/misc/ftdi-elan.c | 26 --------------------------
> >> 1 file changed, 26 deletions(-)
> >>
> >> diff --git a/drivers/usb/misc/ftdi-elan.c b/drivers/usb/misc/ftdi-elan.c
> >> index 76c718a..257efac 100644
> >> --- a/drivers/usb/misc/ftdi-elan.c
> >> +++ b/drivers/usb/misc/ftdi-elan.c
> >> @@ -915,7 +915,6 @@ static int ftdi_elan_respond_engine(struct usb_ftdi *ftdi)
> >> int bytes_read = 0;
> >> int retry_on_empty = 1;
> >> int retry_on_timeout = 3;
> >> - int empty_packets = 0;
> >> read:{
> >> int packet_bytes = 0;
> >> int retval = usb_bulk_msg(ftdi->udev,
> >> @@ -960,31 +959,6 @@ read:{
> >> dev_err(&ftdi->udev->dev, "error = %d with packet_bytes = %d with total %d bytes%s\n",
> >> retval, packet_bytes, bytes_read, diag);
> >> return retval;
> >> - } else if (packet_bytes == 2) {
> >> - unsigned char s0 = ftdi->bulk_in_buffer[0];
> >> - unsigned char s1 = ftdi->bulk_in_buffer[1];
> >> - empty_packets += 1;
> >> - if (s0 == 0x31 && s1 == 0x60) {
> >> - if (retry_on_empty-- > 0) {
> >> - goto more;
> >> - } else
> >> - return 0;
> >> - } else if (s0 == 0x31 && s1 == 0x00) {
> >> - if (retry_on_empty-- > 0) {
> >> - goto more;
> >> - } else
> >> - return 0;
> >> - } else {
> >> - if (retry_on_empty-- > 0) {
> >> - goto more;
> >> - } else
> >> - return 0;
> >> - }
> >> - } else if (packet_bytes == 1) {
> >> - if (retry_on_empty-- > 0) {
> >> - goto more;
> >> - } else
> >> - return 0;
> >
> > Are you _sure_ that these lines are not needed and that the compiler is
> > not really seeing them? As it doesn't look that way to me, what am I
> > missing?
>
> I checked and make sure that All these if/else if branch just do the same thing:
>
> if (retry_on_empty-- > 0) {
> goto more;
> } else
> return 0;
>
> so it can be merged into the last else branch.
>
> Also the variable 'empty_packets' doesn't use in any place, except for self increment
Don't do two different things in the same patch :)
WARNING: multiple messages have this Message-ID (diff)
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: YueHaibing <yuehaibing@huawei.com>
Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: [-next] usb: ftdi-elan: Fix if == else warnings in ftdi_elan_respond_engine
Date: Wed, 23 Jan 2019 14:41:48 +0100 [thread overview]
Message-ID: <20190123134147.GC24700@kroah.com> (raw)
On Wed, Jan 23, 2019 at 09:17:38PM +0800, YueHaibing wrote:
> On 2019/1/23 20:43, Greg KH wrote:
> > On Wed, Jan 23, 2019 at 08:34:42PM +0800, YueHaibing wrote:
> >> ./drivers/usb/misc/ftdi-elan.c:972:10-12: WARNING: possible condition with no effect (if == else)
> >> ./drivers/usb/misc/ftdi-elan.c:983:9-11: WARNING: possible condition with no effect (if == else)
> >> ./drivers/usb/misc/ftdi-elan.c:2052:11-13: WARNING: possible condition with no effect (if == else)
> >>
> >> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
> >
> > You can not just provide the output of a tool as a changelog text,
> > sorry.
> >
> > Please explain what those lines mean, and why you are making the change
> > that you are.
>
> ok, will do that.
>
> >
> >> ---
> >> drivers/usb/misc/ftdi-elan.c | 26 --------------------------
> >> 1 file changed, 26 deletions(-)
> >>
> >> diff --git a/drivers/usb/misc/ftdi-elan.c b/drivers/usb/misc/ftdi-elan.c
> >> index 76c718a..257efac 100644
> >> --- a/drivers/usb/misc/ftdi-elan.c
> >> +++ b/drivers/usb/misc/ftdi-elan.c
> >> @@ -915,7 +915,6 @@ static int ftdi_elan_respond_engine(struct usb_ftdi *ftdi)
> >> int bytes_read = 0;
> >> int retry_on_empty = 1;
> >> int retry_on_timeout = 3;
> >> - int empty_packets = 0;
> >> read:{
> >> int packet_bytes = 0;
> >> int retval = usb_bulk_msg(ftdi->udev,
> >> @@ -960,31 +959,6 @@ read:{
> >> dev_err(&ftdi->udev->dev, "error = %d with packet_bytes = %d with total %d bytes%s\n",
> >> retval, packet_bytes, bytes_read, diag);
> >> return retval;
> >> - } else if (packet_bytes == 2) {
> >> - unsigned char s0 = ftdi->bulk_in_buffer[0];
> >> - unsigned char s1 = ftdi->bulk_in_buffer[1];
> >> - empty_packets += 1;
> >> - if (s0 == 0x31 && s1 == 0x60) {
> >> - if (retry_on_empty-- > 0) {
> >> - goto more;
> >> - } else
> >> - return 0;
> >> - } else if (s0 == 0x31 && s1 == 0x00) {
> >> - if (retry_on_empty-- > 0) {
> >> - goto more;
> >> - } else
> >> - return 0;
> >> - } else {
> >> - if (retry_on_empty-- > 0) {
> >> - goto more;
> >> - } else
> >> - return 0;
> >> - }
> >> - } else if (packet_bytes == 1) {
> >> - if (retry_on_empty-- > 0) {
> >> - goto more;
> >> - } else
> >> - return 0;
> >
> > Are you _sure_ that these lines are not needed and that the compiler is
> > not really seeing them? As it doesn't look that way to me, what am I
> > missing?
>
> I checked and make sure that All these if/else if branch just do the same thing:
>
> if (retry_on_empty-- > 0) {
> goto more;
> } else
> return 0;
>
> so it can be merged into the last else branch.
>
> Also the variable 'empty_packets' doesn't use in any place, except for self increment
Don't do two different things in the same patch :)
next prev parent reply other threads:[~2019-01-23 13:41 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-23 12:34 [PATCH -next] usb: ftdi-elan: Fix if == else warnings in ftdi_elan_respond_engine YueHaibing
2019-01-23 12:34 ` [-next] " YueHaibing
2019-01-23 12:43 ` [PATCH -next] " Greg KH
2019-01-23 12:43 ` [-next] " Greg Kroah-Hartman
2019-01-23 13:17 ` [PATCH -next] " YueHaibing
2019-01-23 13:17 ` [-next] " YueHaibing
2019-01-23 13:41 ` Greg KH [this message]
2019-01-23 13:41 ` Greg Kroah-Hartman
2019-01-23 13:55 ` [PATCH -next] " YueHaibing
2019-01-23 13:55 ` [-next] " YueHaibing
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190123134147.GC24700@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=yuehaibing@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.