Commit 0a15f43b authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

Revert "tty: tty_port: add workqueue to flip TTY buffer" 

This reverts commit d000422a.

It is reported by many to cause boot failures, so must be reverted.

Cc: Xin Zhao <jackzxcui1989@163.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/d1942304-ee30-478d-90fb-279519f3ae81@samsung.com


Reported-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Reported-by: default avatarTommaso Merciai <tommaso.merciai.xr@bp.renesas.com>
Reported-by: default avatarGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d000422a

drivers/tty/pty.c

+4 −10
Original line number Diff line number Diff line
@@ -403,8 +403,6 @@ static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty, 
	o_tty->link = tty;

	tty_port_init(ports[0]);

	tty_port_init(ports[1]);

	tty_port_link_wq(ports[0], system_dfl_wq);

	tty_port_link_wq(ports[1], system_dfl_wq);

	tty_buffer_set_limit(ports[0], 8192);

	tty_buffer_set_limit(ports[1], 8192);

	o_tty->port = ports[0];
@@ -534,16 +532,14 @@ static void __init legacy_pty_init(void) 
	pty_driver = tty_alloc_driver(legacy_count,

			TTY_DRIVER_RESET_TERMIOS |

			TTY_DRIVER_REAL_RAW |

			TTY_DRIVER_DYNAMIC_ALLOC |

			TTY_DRIVER_CUSTOM_WORKQUEUE);

			TTY_DRIVER_DYNAMIC_ALLOC);

	if (IS_ERR(pty_driver))

		panic("Couldn't allocate pty driver");



	pty_slave_driver = tty_alloc_driver(legacy_count,

			TTY_DRIVER_RESET_TERMIOS |

			TTY_DRIVER_REAL_RAW |

			TTY_DRIVER_DYNAMIC_ALLOC |

			TTY_DRIVER_CUSTOM_WORKQUEUE);

			TTY_DRIVER_DYNAMIC_ALLOC);

	if (IS_ERR(pty_slave_driver))

		panic("Couldn't allocate pty slave driver");
@@ -853,8 +849,7 @@ static void __init unix98_pty_init(void) 
			TTY_DRIVER_REAL_RAW |

			TTY_DRIVER_DYNAMIC_DEV |

			TTY_DRIVER_DEVPTS_MEM |

			TTY_DRIVER_DYNAMIC_ALLOC |

			TTY_DRIVER_CUSTOM_WORKQUEUE);

			TTY_DRIVER_DYNAMIC_ALLOC);

	if (IS_ERR(ptm_driver))

		panic("Couldn't allocate Unix98 ptm driver");

	pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
@@ -862,8 +857,7 @@ static void __init unix98_pty_init(void) 
			TTY_DRIVER_REAL_RAW |

			TTY_DRIVER_DYNAMIC_DEV |

			TTY_DRIVER_DEVPTS_MEM |

			TTY_DRIVER_DYNAMIC_ALLOC |

			TTY_DRIVER_CUSTOM_WORKQUEUE);

			TTY_DRIVER_DYNAMIC_ALLOC);

	if (IS_ERR(pts_driver))

		panic("Couldn't allocate Unix98 pts driver");

drivers/tty/tty_buffer.c

+4 −4
Original line number Diff line number Diff line
@@ -76,7 +76,7 @@ void tty_buffer_unlock_exclusive(struct tty_port *port) 
	mutex_unlock(&buf->lock);



	if (restart)

		queue_work(buf->flip_wq, &buf->work);

		queue_work(system_dfl_wq, &buf->work);

}

EXPORT_SYMBOL_GPL(tty_buffer_unlock_exclusive);
@@ -530,7 +530,7 @@ void tty_flip_buffer_push(struct tty_port *port) 
	struct tty_bufhead *buf = &port->buf;



	tty_flip_buffer_commit(buf->tail);

	queue_work(buf->flip_wq, &buf->work);

	queue_work(system_dfl_wq, &buf->work);

}

EXPORT_SYMBOL(tty_flip_buffer_push);
@@ -560,7 +560,7 @@ int tty_insert_flip_string_and_push_buffer(struct tty_port *port, 
		tty_flip_buffer_commit(buf->tail);

	spin_unlock_irqrestore(&port->lock, flags);



	queue_work(buf->flip_wq, &buf->work);

	queue_work(system_dfl_wq, &buf->work);



	return size;

}
@@ -613,7 +613,7 @@ void tty_buffer_set_lock_subclass(struct tty_port *port) 


bool tty_buffer_restart_work(struct tty_port *port)

{

	return queue_work(port->buf.flip_wq, &port->buf.work);

	return queue_work(system_dfl_wq, &port->buf.work);

}



bool tty_buffer_cancel_work(struct tty_port *port)

drivers/tty/tty_io.c

+1 −20
Original line number Diff line number Diff line
@@ -3446,23 +3446,10 @@ int tty_register_driver(struct tty_driver *driver) 
	if (error < 0)

		goto err;



	if (!(driver->flags & TTY_DRIVER_CUSTOM_WORKQUEUE)) {

		driver->flip_wq = alloc_workqueue("%s-flip-wq", WQ_UNBOUND | WQ_SYSFS,

						  0, driver->name);

		if (!driver->flip_wq) {

			error = -ENOMEM;

			goto err_unreg_char;

		}

		for (i = 0; i < driver->num; i++) {

			if (driver->ports[i])

				tty_port_link_driver_wq(driver->ports[i], driver);

		}

	}



	if (driver->flags & TTY_DRIVER_DYNAMIC_ALLOC) {

		error = tty_cdev_add(driver, dev, 0, driver->num);

		if (error)

			goto err_destroy_wq;

			goto err_unreg_char;

	}



	scoped_guard(mutex, &tty_mutex)
@@ -3488,10 +3475,6 @@ int tty_register_driver(struct tty_driver *driver) 
	scoped_guard(mutex, &tty_mutex)

		list_del(&driver->tty_drivers);



err_destroy_wq:

	if (!(driver->flags & TTY_DRIVER_CUSTOM_WORKQUEUE))

		destroy_workqueue(driver->flip_wq);



err_unreg_char:

	unregister_chrdev_region(dev, driver->num);

err:
@@ -3511,8 +3494,6 @@ void tty_unregister_driver(struct tty_driver *driver) 
				driver->num);

	scoped_guard(mutex, &tty_mutex)

		list_del(&driver->tty_drivers);

	if (!(driver->flags & TTY_DRIVER_CUSTOM_WORKQUEUE))

		destroy_workqueue(driver->flip_wq);

}

EXPORT_SYMBOL(tty_unregister_driver);

drivers/tty/tty_port.c

+0 −23
Original line number Diff line number Diff line
@@ -99,26 +99,6 @@ void tty_port_init(struct tty_port *port) 
}

EXPORT_SYMBOL(tty_port_init);



/**

 * tty_port_link_wq - link tty_port and flip workqueue

 * @port: tty_port of the device

 * @flip_wq: workqueue to queue flip buffer work on

 *

 * When %TTY_DRIVER_CUSTOM_WORKQUEUE is used, every tty_port shall be linked to

 * a workqueue manually by this function, otherwise tty_flip_buffer_push() will

 * see %NULL flip_wq pointer on queue_work.

 * When %TTY_DRIVER_CUSTOM_WORKQUEUE is NOT used, the function can be used to

 * link a certain port to a specific workqueue, instead of using the workqueue

 * allocated in tty_register_driver().

 *

 * Note that TTY port API will NOT destroy the workqueue.

 */

void tty_port_link_wq(struct tty_port *port, struct workqueue_struct *flip_wq)

{

	port->buf.flip_wq = flip_wq;

}

EXPORT_SYMBOL_GPL(tty_port_link_wq);



/**

 * tty_port_link_device - link tty and tty_port

 * @port: tty_port of the device
@@ -177,7 +157,6 @@ struct device *tty_port_register_device_attr(struct tty_port *port, 
		const struct attribute_group **attr_grp)

{

	tty_port_link_device(port, driver, index);

	tty_port_link_driver_wq(port, driver);

	return tty_register_device_attr(driver, index, device, drvdata,

			attr_grp);

}
@@ -204,7 +183,6 @@ struct device *tty_port_register_device_attr_serdev(struct tty_port *port, 
	struct device *dev;



	tty_port_link_device(port, driver, index);

	tty_port_link_driver_wq(port, driver);



	dev = serdev_tty_port_register(port, host, parent, driver, index);

	if (PTR_ERR(dev) != -ENODEV) {
@@ -725,7 +703,6 @@ int tty_port_install(struct tty_port *port, struct tty_driver *driver, 
		struct tty_struct *tty)

{

	tty->port = port;

	tty_port_link_driver_wq(port, driver);

	return tty_standard_install(driver, tty);

}

EXPORT_SYMBOL_GPL(tty_port_install);

include/linux/tty_buffer.h

+0 −1
Original line number Diff line number Diff line
@@ -34,7 +34,6 @@ static inline u8 *flag_buf_ptr(struct tty_buffer *b, unsigned int ofs) 


struct tty_bufhead {

	struct tty_buffer *head;	/* Queue head */

	struct workqueue_struct *flip_wq;

	struct work_struct work;

	struct mutex	   lock;

	atomic_t	   priority;