ledtrig-tty: add additional tty state evaluation
Subsystems (2)
v6 cover ledtrig-tty: add additional tty state evaluation
Changes in v6:
==============
This is a paritial rewrite of the changes to make the function for setting the tty evaluation configurable. This change was requested and comment by Greg K-H at the last review [1]. The main changes are.
- Split the changes into smaller commits to make reviewing easier.
- Use a completion to sync the sysfs and the delay scheduler work on shared variables.
- Adding the base-commit to this overview, that reviewer know which base commit I am using.
Base branch is:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Patch [1/7]:
This patch is already included in the tty branch [2], but it is still included in this patchsset, so that the following patches of the base-commit branch could be applied correctly.
Patch [2/7]:
Add a new helper function tty_get_tiocm(). This got already a 'Acked-by: Greg Kroah-Hartman' [3] and is not changed.
Patch [3/7]:
Add missing of freeing an allocated ttyname buffer on trigger deactivation. This is a memory leak fix patch and should also be backported to the 'stable' branches.
Patch [4/7]:
As requested by greg k-h this is more a 'dev_warn' instead of a 'dev_info'. This could also be backported to the 'stable' branches if needed.
Patch [5/7]:
Use a completion to sync for sysfs read/write and the delay scheduler work. I hope I am using the completion correctly. I wasn't sure if I should secure the sysfs read and write access at the same time via a mutex. With this change, the work is also not stopped as it was before when no ttyname was set via sysfs. A tty should always be set when this trigger is used. And is therefore not a problem from my point of view.
Patch [6/7]:
Make rx tx activitate configurable. In the previous implementation, there was still the ttytrigger flag variable. This flag variable was replaced by individual variables in the data struct. Now these variables can be accessed without masking. The commit was rebased and cleaned up to use the completion implementation.
Patch [7/7]:
Adding additional trigger line state sources. The commit was also rebased and cleaned up to use the completion implementation.
Changes in v5:
==============
v5: https://lore.kernel.org/linux-leds/[email protected]/
- Update commit message as request by greg k-h, to make the commit message more generic and not focusing on my use case [1].
- Removing PATCH v4 1/3 from previous set. This has been already applied to tty-testing [2] by greg k-h.
- As requested by greq k-h. I have also made the following changes to PATCH v4 3/3 [3].
* Add a comment to the enum that this is already used for bit evaluation and sysfs read and write.
* Renaming the variable 'unsigned long mode' to
'unsigned long ttytrigger' in the ledtrig_tty_data structure to make it clearer that the selected triggers are stored there.
* Using sysfs_emit() function to dump the requestd ttytrigger to userland.
* Also using the kstrtobool() function to write the selected ttytrigger via the sysfs. This values are booleans.
- I also removed the function ledtrig_tty_evaluate() from my last patchses PATCH v4 3/3 [3]. The new API tty_get_tiocm() function is only called once now and checked for each ttytrigger bit. Previously this function was called for each bit, which is not necessary.
Links:
[1] https://lore.kernel.org/linux-leds/2023102115-stock-scrambled-f7d5@gregkh/
[2] https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git/commit/?h=tty-testing&id=838eb763c3e939a8de8d4c55a17ddcce737685c1
[3] https://lore.kernel.org/linux-leds/[email protected]/
Changes in v4:
==============
v4: https://lore.kernel.org/linux-leds/[email protected]/
- Merging patch 3/4 into patch number 4/4 from previous series, because it fixes a problem that does not exist upstream. This was a note from the build robot regarding my change that I added with previous series. This change was never upstream and therefore this is not relevant.
- Update the commit message of patch 1/3 of this series, that this commit
also changes the 'ndashes' to simple dashes. There were no changes, so I add the 'Reviewed-by' that the commit received before.
- With this patchset version I have reworked my implementation for the evaluation of the additional line state, so that this changes becomes smaller. As basis I have used the staged commits from Christian Marangi that makes this changes to the netdev trigger. This has already been applied to 'for-leds-next-next' by Lee Jones. I adapted this to the tty trigger.
Convert device attr to macro:
https://git.kernel.org/pub/scm/linux/kernel/git/lee/leds.git/commit/drivers/leds/trigger?h=for-leds-next-next&id=509412749002f4bac4c29f2012fff90c08d8afca
Unify sysfs and state handling:
https://git.kernel.org/pub/scm/linux/kernel/git/lee/leds.git/commit/drivers/leds/trigger?h=for-leds-next-next&id=0fd93ac8582627bee9a3c824489f302dff722881
Changes in v3:
==============
v3: https://lore.kernel.org/linux-leds/[email protected]/
- Add missing 'kernel test robot' information to the commit message.
- Additional information added to the commit message
Changes in v2:
==============
v2: https://lore.kernel.org/linux-leds/[email protected]/
- rename new function from tty_get_mget() to tty_get_tiocm() as requested by 'Jiri Slaby'.
- As suggested by 'Jiri Slaby', fixed tabs in function documentation throughout the file '/drivers/tty/tty_io.c' in a separate commit.
- Move the variable definition to the top in function 'ledtrig_tty_work()'.
This was reported by the 'kernel test robot' after my change in v1.
- Also set the 'max_brightness' to 'blink_brightness' if no 'blink_brightness' was set. This fixes a problem at startup when the brightness is still set to 0 and only 'line_*' is evaluated. I looked in the netdev trigger and that's exactly how it's done there.
Changes in v1:
==============
v1: https://lore.kernel.org/linux-leds/[email protected]/
This is a follow-up patchset, based on the mailing list discussion from March 2023 based on the old patchset v8 [1]. I have changed, the LED trigger handling via the sysfs interfaces as suggested by Uwe Kleine-König.
Links:
[1] https://lore.kernel.org/linux-leds/[email protected]/
Florian Eckert (7):
tty: whitespaces in descriptions corrected by replacing tabs with
spaces
tty: add new helper function tty_get_tiocm
leds: ledtrig-tty: free allocated ttyname buffer on deactivate
leds: ledtrig-tty: change logging if get icount failed
leds: ledtrig-tty: replace mutex with completion
leds: ledtrig-tty: make rx tx activitate configurable
leds: ledtrig-tty: add additional line state evaluation
.../ABI/testing/sysfs-class-led-trigger-tty | 56 ++++ drivers/leds/trigger/ledtrig-tty.c | 256 +++++++++++++++--- drivers/tty/tty_io.c | 130 +++++---- include/linux/tty.h | 1 + 4 files changed, 349 insertions(+), 94 deletions(-)
base-commit: ffc253263a1375a65fa6c9f62a893e9767fbebfa
Signature · 1 line
2.30.2
PATCH v6 1/7 tty: whitespaces in descriptions corrected by replacing tabs with spaces
Tabs were used in the function description, to make this look more uniform, the tabs were replaced by spaces where necessary.
While we're at it, I also replaced the 'ndashes' with simple dashes, since only those are supported by sphinx.
--- drivers/tty/tty_io.c | 102 +++++++++++++++++++++---------------------- 1 file changed, 51 insertions(+), 51 deletions(-)
drivers/tty/tty_io.c +51 -51
@@ -159,7 +159,7 @@ static int tty_fasync(int fd, struct file *filp, int on);static void release_tty (struct tty_struct *tty,int idx);/** -* free_tty_struct - free a disused tty +* free_tty_struct - free a disused tty * @tty: tty struct to free * * Free the write buffers, tty queue and tty memory itself.
@@ -233,7 +233,7 @@ static void tty_del_file(struct file *file) }/** -* tty_name - return tty naming +* tty_name - return tty naming * @tty: tty structure * * Convert a tty structure into a name. The name reflects the kernel naming
@@ -295,7 +295,7 @@ static void check_tty_count(struct tty_struct *tty, const char *routine) }/** -* get_tty_driver - find device of a tty +* get_tty_driver - find device of a tty * @device: device identifier * @index: returns the index of the tty *
@@ -320,7 +320,7 @@ static struct tty_driver *get_tty_driver(dev_t device, int *index) }/** -* tty_dev_name_to_number - return dev_t for device name +* tty_dev_name_to_number - return dev_t for device name * @name: user space name of device under /dev * @number: pointer to dev_t that this function will populate *
@@ -372,7 +372,7 @@ EXPORT_SYMBOL_GPL(tty_dev_name_to_number);#ifdef CONFIG_CONSOLE_POLL /** -* tty_find_polling_driver - find device of a polled tty +* tty_find_polling_driver - find device of a polled tty * @name: name string to match * @line: pointer to resulting tty line nr *
@@ -505,7 +505,7 @@ static DEFINE_SPINLOCK(redirect_lock);static struct file *redirect;/** -* tty_wakeup - request more data +* tty_wakeup - request more data * @tty: terminal * * Internal and external helper for wakeups of tty. This function informs the
@@ -529,7 +529,7 @@ void tty_wakeup(struct tty_struct *tty)EXPORT_SYMBOL_GPL (tty_wakeup);/** -* tty_release_redirect - Release a redirect on a pty if present +* tty_release_redirect - Release a redirect on a pty if present * @tty: tty device * * This is available to the pty code so if the master closes, if the slave is a
@@ -550,7 +550,7 @@ static struct file *tty_release_redirect(struct tty_struct *tty) }/** -* __tty_hangup - actual handler for hangup events +* __tty_hangup - actual handler for hangup events * @tty: tty device * @exit_session: if non-zero, signal all foreground group processes *
@@ -673,7 +673,7 @@ static void do_tty_hangup(struct work_struct *work) }/** -* tty_hangup - trigger a hangup event +* tty_hangup - trigger a hangup event * @tty: tty to hangup * * A carrier loss (virtual or otherwise) has occurred on @tty. Schedule a
@@ -687,7 +687,7 @@ void tty_hangup(struct tty_struct *tty)EXPORT_SYMBOL (tty_hangup);/** -* tty_vhangup - process vhangup +* tty_vhangup - process vhangup * @tty: tty to hangup * * The user has asked via system call for the terminal to be hung up. We do
@@ -703,7 +703,7 @@ EXPORT_SYMBOL(tty_vhangup);/** -* tty_vhangup_self - process vhangup for own ctty +* tty_vhangup_self - process vhangup for own ctty * * Perform a vhangup on the current controlling tty */
@@ -719,7 +719,7 @@ void tty_vhangup_self(void) }/** -* tty_vhangup_session - hangup session leader exit +* tty_vhangup_session - hangup session leader exit * @tty: tty to hangup * * The session leader is exiting and hanging up its controlling terminal.
@@ -735,7 +735,7 @@ void tty_vhangup_session(struct tty_struct *tty) }/** -* tty_hung_up_p - was tty hung up +* tty_hung_up_p - was tty hung up * @filp: file pointer of tty * * Return: true if the tty has been subject to a vhangup or a carrier loss
@@ -756,7 +756,7 @@ void __stop_tty(struct tty_struct *tty) }/** -* stop_tty - propagate flow control +* stop_tty - propagate flow control * @tty: tty to stop * * Perform flow control to the driver. May be called on an already stopped
@@ -790,7 +790,7 @@ void __start_tty(struct tty_struct *tty) }/** -* start_tty - propagate flow control +* start_tty - propagate flow control * @tty: tty to start * * Start a tty that has been stopped if at all possible. If @tty was previously
@@ -898,7 +898,7 @@ static ssize_t iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty,/** -* tty_read - read method for tty device files +* tty_read - read method for tty device files * @iocb: kernel I/O control block * @to: destination for the data read *
@@ -1091,7 +1091,7 @@ static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_ }/** -* tty_write - write method for tty device file +* tty_write - write method for tty device file * @iocb: kernel I/O control block * @from: iov_iter with data to write *
@@ -1133,7 +1133,7 @@ ssize_t redirected_tty_write(struct kiocb *iocb, struct iov_iter *iter) }/** -* tty_send_xchar - send priority character +* tty_send_xchar - send priority character * @tty: the tty to send to * @ch: xchar to send *
@@ -1167,7 +1167,7 @@ int tty_send_xchar(struct tty_struct *tty, char ch) }/** -* pty_line_name - generate name for a pty +* pty_line_name - generate name for a pty * @driver: the tty driver in use * @index: the minor number * @p: output buffer of at least 6 bytes
@@ -1188,7 +1188,7 @@ static void pty_line_name(struct tty_driver *driver, int index, char *p) }/** -* tty_line_name - generate name for a tty +* tty_line_name - generate name for a tty * @driver: the tty driver in use * @index: the minor number * @p: output buffer of at least 7 bytes
@@ -1239,7 +1239,7 @@ static struct tty_struct *tty_driver_lookup_tty(struct tty_driver *driver, }/** -* tty_init_termios - helper for termios setup +* tty_init_termios - helper for termios setup * @tty: the tty to set up * * Initialise the termios structure for this tty. This runs under the
@@ -1322,7 +1322,7 @@ static void tty_driver_remove_tty(struct tty_driver *driver, struct tty_struct * }/** -* tty_reopen() - fast re-open of an open tty +* tty_reopen() - fast re-open of an open tty * @tty: the tty to open * * Re-opens on master ptys are not allowed and return -%EIO.
@@ -1366,7 +1366,7 @@ static int tty_reopen(struct tty_struct *tty) }/** -* tty_init_dev - initialise a tty device +* tty_init_dev - initialise a tty device * @driver: tty driver we are opening a device on * @idx: device index *
@@ -1488,7 +1488,7 @@ void tty_save_termios(struct tty_struct *tty)EXPORT_SYMBOL_GPL (tty_save_termios);/** -* tty_flush_works - flush all works of a tty/pty pair +* tty_flush_works - flush all works of a tty/pty pair * @tty: tty device to flush works for (or either end of a pty pair) * * Sync flush all works belonging to @tty (and the 'other' tty).
@@ -1504,7 +1504,7 @@ static void tty_flush_works(struct tty_struct *tty) }/** -* release_one_tty - release tty structure memory +* release_one_tty - release tty structure memory * @work: work of tty we are obliterating * * Releases memory associated with a tty structure, and clears out the
@@ -1552,7 +1552,7 @@ static void queue_release_one_tty(struct kref *kref) }/** -* tty_kref_put - release a tty kref +* tty_kref_put - release a tty kref * @tty: tty device * * Release a reference to the @tty device and if need be let the kref layer
@@ -1566,7 +1566,7 @@ void tty_kref_put(struct tty_struct *tty)EXPORT_SYMBOL (tty_kref_put);/** -* release_tty - release tty structure memory +* release_tty - release tty structure memory * @tty: tty device release * @idx: index of the tty device release *
@@ -1643,7 +1643,7 @@ static int tty_release_checks(struct tty_struct *tty, int idx) }/** -* tty_kclose - closes tty opened by tty_kopen +* tty_kclose - closes tty opened by tty_kopen * @tty: tty device * * Performs the final steps to release and free a tty device. It is the same as
@@ -1673,7 +1673,7 @@ void tty_kclose(struct tty_struct *tty)EXPORT_SYMBOL_GPL (tty_kclose);/** -* tty_release_struct - release a tty struct +* tty_release_struct - release a tty struct * @tty: tty device * @idx: index of the tty *
@@ -1702,7 +1702,7 @@ void tty_release_struct(struct tty_struct *tty, int idx)EXPORT_SYMBOL_GPL (tty_release_struct);/** -* tty_release - vfs callback for close +* tty_release - vfs callback for close * @inode: inode of tty * @filp: file pointer for handle to tty *
@@ -1983,7 +1983,7 @@ static struct tty_struct *tty_kopen(dev_t device, int shared) }/** -* tty_kopen_exclusive - open a tty device for kernel +* tty_kopen_exclusive - open a tty device for kernel * @device: dev_t of device to open * * Opens tty exclusively for kernel. Performs the driver lookup, makes sure
@@ -2003,7 +2003,7 @@ struct tty_struct *tty_kopen_exclusive(dev_t device)EXPORT_SYMBOL_GPL (tty_kopen_exclusive);/** -* tty_kopen_shared - open a tty device for shared in-kernel use +* tty_kopen_shared - open a tty device for shared in-kernel use * @device: dev_t of device to open * * Opens an already existing tty for in-kernel use. Compared to
@@ -2018,7 +2018,7 @@ struct tty_struct *tty_kopen_shared(dev_t device)EXPORT_SYMBOL_GPL (tty_kopen_shared);/** -* tty_open_by_driver - open a tty device +* tty_open_by_driver - open a tty device * @device: dev_t of device to open * @filp: file pointer to tty *
@@ -2086,7 +2086,7 @@ static struct tty_struct *tty_open_by_driver(dev_t device, }/** -* tty_open - open a tty device +* tty_open - open a tty device * @inode: inode of device file * @filp: file pointer to tty *
@@ -2180,7 +2180,7 @@ static int tty_open(struct inode *inode, struct file *filp)/** -* tty_poll - check tty status +* tty_poll - check tty status * @filp: file being polled * @wait: poll wait structures to update *
@@ -2258,7 +2258,7 @@ static int tty_fasync(int fd, struct file *filp, int on)static bool tty_legacy_tiocsti__read_mostly =IS_ENABLED (CONFIG_LEGACY_TIOCSTI );/** -* tiocsti - fake input character +* tiocsti - fake input character * @tty: tty to fake input into * @p: pointer to character *
@@ -2295,7 +2295,7 @@ static int tiocsti(struct tty_struct *tty, char __user *p) }/** -* tiocgwinsz - implement window query ioctl +* tiocgwinsz - implement window query ioctl * @tty: tty * @arg: user buffer for result *
@@ -2316,7 +2316,7 @@ static int tiocgwinsz(struct tty_struct *tty, struct winsize __user *arg) }/** -* tty_do_resize - resize event +* tty_do_resize - resize event * @tty: tty being resized * @ws: new dimensions *
@@ -2346,7 +2346,7 @@ int tty_do_resize(struct tty_struct *tty, struct winsize *ws)EXPORT_SYMBOL (tty_do_resize);/** -* tiocswinsz - implement window size set ioctl +* tiocswinsz - implement window size set ioctl * @tty: tty side of tty * @arg: user buffer for result *
@@ -2373,7 +2373,7 @@ static int tiocswinsz(struct tty_struct *tty, struct winsize __user *arg) }/** -* tioccons - allow admin to move logical console +* tioccons - allow admin to move logical console * @file: the file to become console * * Allow the administrator to move the redirected console device.
@@ -2412,7 +2412,7 @@ static int tioccons(struct file *file) }/** -* tiocsetd - set line discipline +* tiocsetd - set line discipline * @tty: tty device * @p: pointer to user data *
@@ -2434,7 +2434,7 @@ static int tiocsetd(struct tty_struct *tty, int __user *p) }/** -* tiocgetd - get line discipline +* tiocgetd - get line discipline * @tty: tty device * @p: pointer to user data *
@@ -2457,7 +2457,7 @@ static int tiocgetd(struct tty_struct *tty, int __user *p) }/** -* send_break - performed time break +* send_break - performed time break * @tty: device to break on * @duration: timeout in mS *
@@ -2495,7 +2495,7 @@ static int send_break(struct tty_struct *tty, unsigned int duration) }/** -* tty_tiocmget - get modem status +* tty_tiocmget - get modem status * @tty: tty device * @p: pointer to result *
@@ -2518,7 +2518,7 @@ static int tty_tiocmget(struct tty_struct *tty, int __user *p) }/** -* tty_tiocmset - set modem status +* tty_tiocmset - set modem status * @tty: tty device * @cmd: command - clear bits, set bits or set all * @p: pointer to desired bits
@@ -2559,7 +2559,7 @@ static int tty_tiocmset(struct tty_struct *tty, unsigned int cmd, }/** -* tty_get_icount - get tty statistics +* tty_get_icount - get tty statistics * @tty: tty device * @icount: output parameter *
@@ -3122,7 +3122,7 @@ struct tty_struct *alloc_tty_struct(struct tty_driver *driver, int idx) }/** -* tty_put_char - write one character to a tty +* tty_put_char - write one character to a tty * @tty: tty * @ch: character to write *
@@ -3300,7 +3300,7 @@ void tty_unregister_device(struct tty_driver *driver, unsigned index)EXPORT_SYMBOL (tty_unregister_device);/** -* __tty_alloc_driver -- allocate tty driver +* __tty_alloc_driver - allocate tty driver * @lines: count of lines this driver can handle at most * @owner: module which is responsible for this driver * @flags: some of %TTY_DRIVER_ flags, will be set in driver->flags
@@ -3393,7 +3393,7 @@ static void destruct_tty_driver(struct kref *kref) }/** -* tty_driver_kref_put -- drop a reference to a tty driver +* tty_driver_kref_put - drop a reference to a tty driver * @driver: driver of which to drop the reference * * The final put will destroy and free up the driver.
@@ -3405,7 +3405,7 @@ void tty_driver_kref_put(struct tty_driver *driver)EXPORT_SYMBOL (tty_driver_kref_put);/** -* tty_register_driver -- register a tty driver +* tty_register_driver - register a tty driver * @driver: driver to register * * Called by a tty driver to register itself.
@@ -3470,7 +3470,7 @@ int tty_register_driver(struct tty_driver *driver)EXPORT_SYMBOL (tty_register_driver);/** -* tty_unregister_driver -- unregister a tty driver +* tty_unregister_driver - unregister a tty driver * @driver: driver to unregister * * Called by a tty driver to unregister itself.
Signature · 1 line
2.30.2
PATCH v6 2/7 tty: add new helper function tty_get_tiocm
In reply to Florian EckertThere is no in-kernel function to get the status register of a tty device like the TIOCMGET ioctl returns to userspace. Create a new function, tty_get_tiocm(), to obtain the status register that other portions of the kernel can call if they need this information, and move the existing internal tty_tiocmget() function to use this interface.
--- drivers/tty/tty_io.c | 28 ++++++++++++++++++++++------ include/linux/tty.h | 1 + 2 files changed, 23 insertions(+), 6 deletions(-)
drivers/tty/tty_io.c +22 -6
@@ -2494,6 +2494,24 @@ static int send_break(struct tty_struct *tty, unsigned int duration)return retval; } +/** +* tty_get_tiocm - get tiocm status register +* @tty: tty device +* +* Obtain the modem status bits from the tty driver if the feature +* is supported. +*/ +int tty_get_tiocm (struct tty_struct *tty) +{ +int retval = -ENOTTY ; + +if (tty->ops->tiocmget) + retval = tty->ops->tiocmget (tty); + +return retval; +} +EXPORT_SYMBOL_GPL (tty_get_tiocm); +/** * tty_tiocmget - get modem status * @tty: tty device
@@ -2506,14 +2524,12 @@ static int send_break(struct tty_struct *tty, unsigned int duration)*/ static int tty_tiocmget (struct tty_struct *tty,int __user *p) { -int retval = -ENOTTY ; +int retval; -if (tty->ops->tiocmget) { - retval = tty->ops->tiocmget (tty); + retval =tty_get_tiocm (tty); +if (retval >=0 ) + retval =put_user (retval, p); -if (retval >=0 ) - retval =put_user (retval, p); - }return retval; }
include/linux/tty.h +1 -0
@@ -421,6 +421,7 @@ int tty_unthrottle_safe(struct tty_struct *tty);int tty_do_resize (struct tty_struct *tty,struct winsize *ws);int tty_get_icount (struct tty_struct *tty,struct serial_icounter_struct *icount); +int tty_get_tiocm (struct tty_struct *tty);int is_current_pgrp_orphaned (void );void tty_hangup (struct tty_struct *tty);void tty_vhangup (struct tty_struct *tty);
Signature · 1 line
2.30.2
PATCH v6 3/7 leds: ledtrig-tty: free allocated ttyname buffer on deactivate
In reply to Florian EckertThe ttyname buffer for the ledtrig_tty_data struct is allocated in the sysfs ttyname_store() function. This buffer must be released on trigger deactivation. This was missing and is thus a memory leak.
While we are at it, the tty handler in the ledtrig_tty_data struct should also be returned in case of the trigger deactivation call.
--- drivers/leds/trigger/ledtrig-tty.c | 4 ++++ 1 file changed, 4 insertions(+)
drivers/leds/trigger/ledtrig-tty.c +4 -0
@@ -168,6 +168,10 @@ static void ledtrig_tty_deactivate(struct led_classdev *led_cdev)cancel_delayed_work_sync (&trigger_data->dwork); +kfree (trigger_data->ttyname); +tty_kref_put (trigger_data->tty); + trigger_data->tty =NULL ; +kfree (trigger_data); }
Signature · 1 line
2.30.2
Re: [Patch v6 3/7] leds: ledtrig-tty: free allocated ttyname buffer on deactivate
Florian Eckert wrote on 2023-10-30 11:04:
Quoted 3 lines
The ttyname buffer for the
ledtrig_tty_datastruct is allocated in the sysfsttyname_store()function. This buffer must be released on trigger deactivation. This was missing and is thus a memory leak.
Shouldn´t there be a Fixes tag here?
And as a side note: you have patches 1..7/7 and a cover letter 0/8 ?
Maarten
PATCH v6 4/7 leds: ledtrig-tty: change logging if get icount failed
In reply to Florian EckertChange the log level from info to warn, because there is something wrong. That is more a warn message than an info message.
While we are at it, the device prefix is also changed, as this is the led device and not the tty device that generates this message.
--- drivers/leds/trigger/ledtrig-tty.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
drivers/leds/trigger/ledtrig-tty.c +3 -3
@@ -83,6 +83,7 @@ static void ledtrig_tty_work(struct work_struct *work)struct ledtrig_tty_data *trigger_data = container_of(work, struct ledtrig_tty_data, dwork.work);struct serial_icounter_struct icount; +struct led_classdev *led_cdev = trigger_data->led_cdev;int ret;mutex_lock (&trigger_data->mutex);
@@ -117,7 +118,7 @@ static void ledtrig_tty_work(struct work_struct *work) ret =tty_get_icount (trigger_data->tty, &icount);if (ret) { -dev_info (trigger_data->tty->dev,"Failed to get icount, stopped polling\n" ); +dev_warn (led_cdev->dev,"Failed to get icount, stop polling\n" );mutex_unlock (&trigger_data->mutex);return ; }
@@ -126,8 +127,7 @@ static void ledtrig_tty_work(struct work_struct *work) icount.tx != trigger_data->tx) {unsigned long interval =LEDTRIG_TTY_INTERVAL ; -led_blink_set_oneshot (trigger_data->led_cdev, &interval, - &interval,0 ); +led_blink_set_oneshot (led_cdev, &interval, &interval,0 ); trigger_data->rx = icount.rx; trigger_data->tx = icount.tx;
Signature · 1 line
2.30.2
PATCH v6 5/7 leds: ledtrig-tty: replace mutex with completion
In reply to Florian EckertWith this commit, the mutex handling is replaced by the completion handling. When handling mutex, it must always be ensured that the held mutex is also released again. This is more error-prone should the number of code paths increase.
This is a preparatory commit to make the trigger more configurable via additional sysfs parameters. With this change, the worker always runs and is no longer stopped if no ttyname is set.
--- drivers/leds/trigger/ledtrig-tty.c | 60 +++++++++++++++--------------- 1 file changed, 31 insertions(+), 29 deletions(-)
drivers/leds/trigger/ledtrig-tty.c +31 -29
@@ -1,5 +1,6 @@// SPDX-License-Identifier: GPL-2.0 +#include <linux/completion.h> #include <linux/delay.h> #include <linux/leds.h> #include <linux/module.h>
@@ -12,15 +13,24 @@struct ledtrig_tty_data {struct led_classdev *led_cdev;struct delayed_work dwork; -struct mutex mutex; +struct completion sysfs;const char *ttyname;struct tty_struct *tty;int rx, tx; }; -static void ledtrig_tty_restart (struct ledtrig_tty_data *trigger_data) +static int ledtrig_tty_waitforcompletion (struct device *dev) { -schedule_delayed_work (&trigger_data->dwork,0 ); +struct ledtrig_tty_data *trigger_data =led_trigger_get_drvdata (dev); +int ret; + + ret =wait_for_completion_timeout (&trigger_data->sysfs, +msecs_to_jiffies (LEDTRIG_TTY_INTERVAL *20 )); + +if (ret ==0 ) +return -ETIMEDOUT ; + +return ret; } static ssize_t ttyname_show(struct device *dev,
@@ -28,14 +38,16 @@ static ssize_t ttyname_show(struct device *dev, {struct ledtrig_tty_data *trigger_data =led_trigger_get_drvdata (dev);ssize_t len =0 ; +int completion; -mutex_lock (&trigger_data->mutex); +reinit_completion (&trigger_data->sysfs); + completion =ledtrig_tty_waitforcompletion (dev); +if (completion <0 ) +return completion;if (trigger_data->ttyname) len =sprintf (buf,"%s\n" , trigger_data->ttyname); -mutex_unlock (&trigger_data->mutex); -return len; }
@@ -46,7 +58,7 @@ static ssize_t ttyname_store(struct device *dev,struct ledtrig_tty_data *trigger_data =led_trigger_get_drvdata (dev);char *ttyname;ssize_t ret = size; -bool running; +int completion;if (size >0 && buf[size -1 ] =='\n' ) size -=1 ;
@@ -59,9 +71,10 @@ static ssize_t ttyname_store(struct device *dev, ttyname =NULL ; } -mutex_lock (&trigger_data->mutex); - - running = trigger_data->ttyname !=NULL ; +reinit_completion (&trigger_data->sysfs); + completion =ledtrig_tty_waitforcompletion (dev); +if (completion <0 ) +return completion;kfree (trigger_data->ttyname);tty_kref_put (trigger_data->tty);
@@ -69,11 +82,6 @@ static ssize_t ttyname_store(struct device *dev, trigger_data->ttyname = ttyname; -mutex_unlock (&trigger_data->mutex); - -if (ttyname && !running) -ledtrig_tty_restart (trigger_data); -return ret; }static DEVICE_ATTR_RW (ttyname);
@@ -86,13 +94,8 @@ static void ledtrig_tty_work(struct work_struct *work)struct led_classdev *led_cdev = trigger_data->led_cdev;int ret; -mutex_lock (&trigger_data->mutex); - -if (!trigger_data->ttyname) { -/* exit without rescheduling */ -mutex_unlock (&trigger_data->mutex); -return ; - } +if (!trigger_data->ttyname) + goto out;/* try to get the tty corresponding to $ttyname */ if (!trigger_data->tty) {
@@ -117,11 +120,8 @@ static void ledtrig_tty_work(struct work_struct *work) } ret =tty_get_icount (trigger_data->tty, &icount); -if (ret) { -dev_warn (led_cdev->dev,"Failed to get icount, stop polling\n" ); -mutex_unlock (&trigger_data->mutex); -return ; - } +if (ret) + goto out;if (icount.rx != trigger_data->rx || icount.tx != trigger_data->tx) {
@@ -134,7 +134,7 @@ static void ledtrig_tty_work(struct work_struct *work) } out: -mutex_unlock (&trigger_data->mutex); +complete_all (&trigger_data->sysfs);schedule_delayed_work (&trigger_data->dwork,msecs_to_jiffies (LEDTRIG_TTY_INTERVAL *2 )); }
@@ -157,7 +157,9 @@ static int ledtrig_tty_activate(struct led_classdev *led_cdev)INIT_DELAYED_WORK (&trigger_data->dwork, ledtrig_tty_work); trigger_data->led_cdev = led_cdev; -mutex_init (&trigger_data->mutex); +init_completion (&trigger_data->sysfs); + +schedule_delayed_work (&trigger_data->dwork,0 );return 0 ; }
Signature · 1 line
2.30.2
PATCH v6 6/7 leds: ledtrig-tty: make rx tx activitate configurable
In reply to Florian EckertUntil now, the LED blinks when data is sent via the tty (rx/tx). This is not configurable.
This change adds the possibility to make the indication for the direction of the transmitted data independently controllable via the new rx and tx sysfs entries.
- rx:
Signal reception (rx) of data on the named tty device. If set to 0, the LED will not blink on reception. If set to 1 (default), the LED will blink on reception.
- tx:
Signal transmission (tx) of data on the named tty device. If set to 0, the LED will not blink on transmission. If set to 1 (default), the LED will blink on transmission.
This new sysfs entry are on by default. Thus the trigger behaves as before this change.
--- .../ABI/testing/sysfs-class-led-trigger-tty | 16 +++ drivers/leds/trigger/ledtrig-tty.c | 124 ++++++++++++++++-- 2 files changed, 130 insertions(+), 10 deletions(-)
Documentation/ABI/testing/sysfs-class-led-trigger-tty +16 -0
@@ -4,3 +4,19 @@ KernelVersion: 5.10 Contact: [email protected] Description: Specifies the tty device name of the triggering tty + +What: /sys/class/leds/<led>/rx +Date: February 2024 +KernelVersion: 6.8 +Description: + Signal reception (rx) of data on the named tty device. + If set to 0, the LED will not blink on reception. + If set to 1 (default), the LED will blink on reception. + +What: /sys/class/leds/<led>/tx +Date: February 2024 +KernelVersion: 6.8 +Description: + Signal transmission (tx) of data on the named tty device. + If set to 0, the LED will not blink on transmission. + If set to 1 (default), the LED will blink on transmission.
drivers/leds/trigger/ledtrig-tty.c +114 -10
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Signature · 1 line
2.30.2
PATCH v6 7/7 leds: ledtrig-tty: add additional line state evaluation
In reply to Florian EckertThe serial tty interface also supports additional input signals,that can also be evaluated within this trigger. This change is adding the following additional input sources, which could be controlled via the '/sys/class/<leds>/' sysfs interface.
Explanation:
DCE = Data Communication Equipment (Modem)
DTE = Data Terminal Equipment (Computer)
- cts:
DCE is ready to accept data from the DTE (CTS = Clear To Send). If the line state is detected, the LED is switched on.
If set to 0 (default), the LED will not evaluate CTS. If set to 1, the LED will evaluate CTS.
- dsr:
DCE is ready to receive and send data (DSR = Data Set Ready). If the line state is detected, the LED is switched on.
If set to 0 (default), the LED will not evaluate DSR.
If set to 1, the LED will evaluate DSR.
- dcd:
DTE is receiving a carrier from the DCE (DCD = Data Carrier Detect). If the line state is detected, the LED is switched on.
If set to 0 (default), the LED will not evaluate DCD.
If set to 1, the LED will evaluate DCD.
- rng:
DCE has detected an incoming ring signal on the telephone line (RNG = Ring Indicator). If the line state is detected, the LED is switched on.
If set to 0 (default), the LED will not evaluate RNG. If set to 1, the LED will evaluate RNG.
--- .../ABI/testing/sysfs-class-led-trigger-tty | 40 +++++++++++ drivers/leds/trigger/ledtrig-tty.c | 72 +++++++++++++++++++ 2 files changed, 112 insertions(+)
Documentation/ABI/testing/sysfs-class-led-trigger-tty +40 -0
@@ -20,3 +20,43 @@ Description: Signal transmission (tx) of data on the named tty device. If set to 0, the LED will not blink on transmission. If set to 1 (default), the LED will blink on transmission. + +What: /sys/class/leds/<led>/cts +Date: February 2024 +KernelVersion: 6.8 +Description: + CTS = Clear To Send + DCE is ready to accept data from the DTE. + If the line state is detected, the LED is switched on. + If set to 0 (default), the LED will not evaluate CTS. + If set to 1, the LED will evaluate CTS. + +What: /sys/class/leds/<led>/dsr +Date: February 2024 +KernelVersion: 6.8 +Description: + DSR = Data Set Ready + DCE is ready to receive and send data. + If the line state is detected, the LED is switched on. + If set to 0 (default), the LED will not evaluate DSR. + If set to 1, the LED will evaluate DSR. + +What: /sys/class/leds/<led>/dcd +Date: February 2024 +KernelVersion: 6.8 +Description: + DCD = Data Carrier Detect + DTE is receiving a carrier from the DCE. + If the line state is detected, the LED is switched on. + If set to 0 (default), the LED will not evaluate CAR (DCD). + If set to 1, the LED will evaluate CAR (DCD). + +What: /sys/class/leds/<led>/rng +Date: February 2024 +KernelVersion: 6.8 +Description: + RNG = Ring Indicator + DCE has detected an incoming ring signal on the telephone + line. If the line state is detected, the LED is switched on. + If set to 0 (default), the LED will not evaluate RNG. + If set to 1, the LED will evaluate RNG.
drivers/leds/trigger/ledtrig-tty.c +72 -0
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Signature · 1 line
2.30.2