| Message ID | 20180529153107.12791-1-gregkh@linuxfoundation.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
+Guenter On Tue, May 29, 2018 at 05:30:46PM +0200, Greg Kroah-Hartman wrote: > When calling debugfs functions, there is no need to ever check the > return value. The function can work or not, but the code logic should > never do something different based on this. > > Clean up the tcpm.c code to not care about this, turns out no one was > even checking the return value of this function, so it didn't matter. > > Note, I do not think this code can be removed in a running system, as > the debugfs root directory will stick around, that should be fixed > someday... > > Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Revieved-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > --- > drivers/usb/typec/tcpm.c | 11 +++-------- > 1 file changed, 3 insertions(+), 8 deletions(-) > > diff --git a/drivers/usb/typec/tcpm.c b/drivers/usb/typec/tcpm.c > index 0ccd2ce1eb59..8a201dd53d36 100644 > --- a/drivers/usb/typec/tcpm.c > +++ b/drivers/usb/typec/tcpm.c > @@ -566,21 +566,16 @@ DEFINE_SHOW_ATTRIBUTE(tcpm_debug); > > static struct dentry *rootdir; > > -static int tcpm_debugfs_init(struct tcpm_port *port) > +static void tcpm_debugfs_init(struct tcpm_port *port) > { > mutex_init(&port->logbuffer_lock); > /* /sys/kernel/debug/tcpm/usbcX */ > - if (!rootdir) { > + if (!rootdir) > rootdir = debugfs_create_dir("tcpm", NULL); > - if (!rootdir) > - return -ENOMEM; > - } > > port->dentry = debugfs_create_file(dev_name(port->dev), > S_IFREG | 0444, rootdir, > port, &tcpm_debug_fops); > - > - return 0; > } > > static void tcpm_debugfs_exit(struct tcpm_port *port) > @@ -595,7 +590,7 @@ static void tcpm_log(const struct tcpm_port *port, const char *fmt, ...) { } > __printf(2, 3) > static void tcpm_log_force(struct tcpm_port *port, const char *fmt, ...) { } > static void tcpm_log_source_caps(struct tcpm_port *port) { } > -static int tcpm_debugfs_init(const struct tcpm_port *port) { return 0; } > +static void tcpm_debugfs_init(const struct tcpm_port *port) { } > static void tcpm_debugfs_exit(const struct tcpm_port *port) { } > > #endif > -- > 2.17.0 Thanks,
On Wed, May 30, 2018 at 01:30:20PM +0300, Heikki Krogerus wrote: > +Guenter > > On Tue, May 29, 2018 at 05:30:46PM +0200, Greg Kroah-Hartman wrote: > > When calling debugfs functions, there is no need to ever check the > > return value. The function can work or not, but the code logic should > > never do something different based on this. > > > > Clean up the tcpm.c code to not care about this, turns out no one was > > even checking the return value of this function, so it didn't matter. > > > > Note, I do not think this code can be removed in a running system, as > > the debugfs root directory will stick around, that should be fixed > > someday... As Guenter pointed out to a different patch in this series, the code is correct as-is, I read it wrong. I'll delete this sentance from the changelog when I apply it. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/30/2018 03:30 AM, Heikki Krogerus wrote: > +Guenter > > On Tue, May 29, 2018 at 05:30:46PM +0200, Greg Kroah-Hartman wrote: >> When calling debugfs functions, there is no need to ever check the >> return value. The function can work or not, but the code logic should >> never do something different based on this. >> >> Clean up the tcpm.c code to not care about this, turns out no one was >> even checking the return value of this function, so it didn't matter. >> >> Note, I do not think this code can be removed in a running system, as >> the debugfs root directory will stick around, that should be fixed >> someday... >> Yes. I'll send a patch. >> Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> >> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > Revieved-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> > >> --- >> drivers/usb/typec/tcpm.c | 11 +++-------- >> 1 file changed, 3 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/usb/typec/tcpm.c b/drivers/usb/typec/tcpm.c >> index 0ccd2ce1eb59..8a201dd53d36 100644 >> --- a/drivers/usb/typec/tcpm.c >> +++ b/drivers/usb/typec/tcpm.c >> @@ -566,21 +566,16 @@ DEFINE_SHOW_ATTRIBUTE(tcpm_debug); >> >> static struct dentry *rootdir; >> >> -static int tcpm_debugfs_init(struct tcpm_port *port) >> +static void tcpm_debugfs_init(struct tcpm_port *port) >> { >> mutex_init(&port->logbuffer_lock); >> /* /sys/kernel/debug/tcpm/usbcX */ >> - if (!rootdir) { >> + if (!rootdir) >> rootdir = debugfs_create_dir("tcpm", NULL); >> - if (!rootdir) >> - return -ENOMEM; >> - } >> >> port->dentry = debugfs_create_file(dev_name(port->dev), >> S_IFREG | 0444, rootdir, >> port, &tcpm_debug_fops); >> - >> - return 0; >> } >> >> static void tcpm_debugfs_exit(struct tcpm_port *port) >> @@ -595,7 +590,7 @@ static void tcpm_log(const struct tcpm_port *port, const char *fmt, ...) { } >> __printf(2, 3) >> static void tcpm_log_force(struct tcpm_port *port, const char *fmt, ...) { } >> static void tcpm_log_source_caps(struct tcpm_port *port) { } >> -static int tcpm_debugfs_init(const struct tcpm_port *port) { return 0; } >> +static void tcpm_debugfs_init(const struct tcpm_port *port) { } >> static void tcpm_debugfs_exit(const struct tcpm_port *port) { } >> >> #endif >> -- >> 2.17.0 > > Thanks, > -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 05/30/2018 03:36 AM, Greg Kroah-Hartman wrote: > On Wed, May 30, 2018 at 01:30:20PM +0300, Heikki Krogerus wrote: >> +Guenter >> >> On Tue, May 29, 2018 at 05:30:46PM +0200, Greg Kroah-Hartman wrote: >>> When calling debugfs functions, there is no need to ever check the >>> return value. The function can work or not, but the code logic should >>> never do something different based on this. >>> >>> Clean up the tcpm.c code to not care about this, turns out no one was >>> even checking the return value of this function, so it didn't matter. >>> >>> Note, I do not think this code can be removed in a running system, as >>> the debugfs root directory will stick around, that should be fixed >>> someday... > > As Guenter pointed out to a different patch in this series, the code is > correct as-is, I read it wrong. I'll delete this sentance from the > changelog when I apply it. > Well, maybe I did not have enough coffee, but after looking into the code, I do think it is missing debugfs_remove(rootdir); in the removal path. See commit c9359f416 in linux-next. You had tried to replace that with debugfs_remove_recursive() in the fusb302 driver. Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, May 30, 2018 at 06:42:49AM -0700, Guenter Roeck wrote: > On 05/30/2018 03:36 AM, Greg Kroah-Hartman wrote: > > On Wed, May 30, 2018 at 01:30:20PM +0300, Heikki Krogerus wrote: > > > +Guenter > > > > > > On Tue, May 29, 2018 at 05:30:46PM +0200, Greg Kroah-Hartman wrote: > > > > When calling debugfs functions, there is no need to ever check the > > > > return value. The function can work or not, but the code logic should > > > > never do something different based on this. > > > > > > > > Clean up the tcpm.c code to not care about this, turns out no one was > > > > even checking the return value of this function, so it didn't matter. > > > > > > > > Note, I do not think this code can be removed in a running system, as > > > > the debugfs root directory will stick around, that should be fixed > > > > someday... > > > > As Guenter pointed out to a different patch in this series, the code is > > correct as-is, I read it wrong. I'll delete this sentance from the > > changelog when I apply it. > > > Well, maybe I did not have enough coffee, but after looking into the code, > I do think it is missing > debugfs_remove(rootdir); > in the removal path. See commit c9359f416 in linux-next. You had tried > to replace that with debugfs_remove_recursive() in the fusb302 driver. Yes, I think you are correct. greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/usb/typec/tcpm.c b/drivers/usb/typec/tcpm.c index 0ccd2ce1eb59..8a201dd53d36 100644 --- a/drivers/usb/typec/tcpm.c +++ b/drivers/usb/typec/tcpm.c @@ -566,21 +566,16 @@ DEFINE_SHOW_ATTRIBUTE(tcpm_debug); static struct dentry *rootdir; -static int tcpm_debugfs_init(struct tcpm_port *port) +static void tcpm_debugfs_init(struct tcpm_port *port) { mutex_init(&port->logbuffer_lock); /* /sys/kernel/debug/tcpm/usbcX */ - if (!rootdir) { + if (!rootdir) rootdir = debugfs_create_dir("tcpm", NULL); - if (!rootdir) - return -ENOMEM; - } port->dentry = debugfs_create_file(dev_name(port->dev), S_IFREG | 0444, rootdir, port, &tcpm_debug_fops); - - return 0; } static void tcpm_debugfs_exit(struct tcpm_port *port) @@ -595,7 +590,7 @@ static void tcpm_log(const struct tcpm_port *port, const char *fmt, ...) { } __printf(2, 3) static void tcpm_log_force(struct tcpm_port *port, const char *fmt, ...) { } static void tcpm_log_source_caps(struct tcpm_port *port) { } -static int tcpm_debugfs_init(const struct tcpm_port *port) { return 0; } +static void tcpm_debugfs_init(const struct tcpm_port *port) { } static void tcpm_debugfs_exit(const struct tcpm_port *port) { } #endif
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Clean up the tcpm.c code to not care about this, turns out no one was even checking the return value of this function, so it didn't matter. Note, I do not think this code can be removed in a running system, as the debugfs root directory will stick around, that should be fixed someday... Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/usb/typec/tcpm.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-)