diff options
Diffstat (limited to 'drivers/usb/serial/digi_acceleport.c')
| -rw-r--r-- | drivers/usb/serial/digi_acceleport.c | 216 |
1 files changed, 0 insertions, 216 deletions
diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c index e92cbefc0f88..3786e9544ae0 100644 --- a/drivers/usb/serial/digi_acceleport.c +++ b/drivers/usb/serial/digi_acceleport.c @@ -13,222 +13,6 @@ * * Peter Berger (pberger@brimson.com) * Al Borchers (borchers@steinerpoint.com) -* -* (12/03/2001) gkh -* switched to using port->port.count instead of private version. -* Removed port->active -* -* (04/08/2001) gb -* Identify version on module load. -* -* (11/01/2000) Adam J. Richter -* usb_device_id table support -* -* (11/01/2000) pberger and borchers -* -- Turned off the USB_DISABLE_SPD flag for write bulk urbs--it caused -* USB 4 ports to hang on startup. -* -- Serialized access to write urbs by adding the dp_write_urb_in_use -* flag; otherwise, the driver caused SMP system hangs. Watching the -* urb status is not sufficient. -* -* (10/05/2000) gkh -* -- Fixed bug with urb->dev not being set properly, now that the usb -* core needs it. -* -* (8/8/2000) pberger and borchers -* -- Fixed close so that -* - it can timeout while waiting for transmit idle, if needed; -* - it ignores interrupts when flushing the port, turning -* of modem signalling, and so on; -* - it waits for the flush to really complete before returning. -* -- Read_bulk_callback and write_bulk_callback check for a closed -* port before using the tty struct or writing to the port. -* -- The two changes above fix the oops caused by interrupted closes. -* -- Added interruptible args to write_oob_command and set_modem_signals -* and added a timeout arg to transmit_idle; needed for fixes to -* close. -* -- Added code for rx_throttle and rx_unthrottle so that input flow -* control works. -* -- Added code to set overrun, parity, framing, and break errors -* (untested). -* -- Set USB_DISABLE_SPD flag for write bulk urbs, so no 0 length -* bulk writes are done. These hung the Digi USB device. The -* 0 length bulk writes were a new feature of usb-uhci added in -* the 2.4.0-test6 kernels. -* -- Fixed mod inc race in open; do mod inc before sleeping to wait -* for a close to finish. -* -* (7/31/2000) pberger -* -- Fixed bugs with hardware handshaking: -* - Added code to set/clear tty->hw_stopped in digi_read_oob_callback() -* and digi_set_termios() -* -- Added code in digi_set_termios() to -* - add conditional in code handling transition from B0 to only -* set RTS if RTS/CTS flow control is either not in use or if -* the port is not currently throttled. -* - handle turning off CRTSCTS. -* -* (7/30/2000) borchers -* -- Added support for more than one Digi USB device by moving -* globals to a private structure in the pointed to from the -* usb_serial structure. -* -- Moved the modem change and transmit idle wait queues into -* the port private structure, so each port has its own queue -* rather than sharing global queues. -* -- Added support for break signals. -* -* (7/25/2000) pberger -* -- Added USB-2 support. Note: the USB-2 supports 3 devices: two -* serial and a parallel port. The parallel port is implemented -* as a serial-to-parallel converter. That is, the driver actually -* presents all three USB-2 interfaces as serial ports, but the third -* one physically connects to a parallel device. Thus, for example, -* one could plug a parallel printer into the USB-2's third port, -* but from the kernel's (and userland's) point of view what's -* actually out there is a serial device. -* -* (7/15/2000) borchers -* -- Fixed race in open when a close is in progress. -* -- Keep count of opens and dec the module use count for each -* outstanding open when shutdown is called (on disconnect). -* -- Fixed sanity checks in read_bulk_callback and write_bulk_callback -* so pointers are checked before use. -* -- Split read bulk callback into in band and out of band -* callbacks, and no longer restart read chains if there is -* a status error or a sanity error. This fixed the seg -* faults and other errors we used to get on disconnect. -* -- Port->active is once again a flag as usb-serial intended it -* to be, not a count. Since it was only a char it would -* have been limited to 256 simultaneous opens. Now the open -* count is kept in the port private structure in dp_open_count. -* -- Added code for modularization of the digi_acceleport driver. -* -* (6/27/2000) pberger and borchers -* -- Zeroed out sync field in the wakeup_task before first use; -* otherwise the uninitialized value might prevent the task from -* being scheduled. -* -- Initialized ret value to 0 in write_bulk_callback, otherwise -* the uninitialized value could cause a spurious debugging message. -* -* (6/22/2000) pberger and borchers -* -- Made cond_wait_... inline--apparently on SPARC the flags arg -* to spin_lock_irqsave cannot be passed to another function -* to call spin_unlock_irqrestore. Thanks to Pauline Middelink. -* -- In digi_set_modem_signals the inner nested spin locks use just -* spin_lock() rather than spin_lock_irqsave(). The old code -* mistakenly left interrupts off. Thanks to Pauline Middelink. -* -- copy_from_user (which can sleep) is no longer called while a -* spinlock is held. We copy to a local buffer before getting -* the spinlock--don't like the extra copy but the code is simpler. -* -- Printk and dbg are no longer called while a spin lock is held. -* -* (6/4/2000) pberger and borchers -* -- Replaced separate calls to spin_unlock_irqrestore and -* interruptible_sleep_on_timeout with a new function -* cond_wait_interruptible_timeout_irqrestore. This eliminates -* the race condition where the wake up could happen after -* the unlock and before the sleep. -* -- Close now waits for output to drain. -* -- Open waits until any close in progress is finished. -* -- All out of band responses are now processed, not just the -* first in a USB packet. -* -- Fixed a bug that prevented the driver from working when the -* first Digi port was not the first USB serial port--the driver -* was mistakenly using the external USB serial port number to -* try to index into its internal ports. -* -- Fixed an SMP bug -- write_bulk_callback is called directly from -* an interrupt, so spin_lock_irqsave/spin_unlock_irqrestore are -* needed for locks outside write_bulk_callback that are also -* acquired by write_bulk_callback to prevent deadlocks. -* -- Fixed support for select() by making digi_chars_in_buffer() -* return 256 when -EINPROGRESS is set, as the line discipline -* code in n_tty.c expects. -* -- Fixed an include file ordering problem that prevented debugging -* messages from working. -* -- Fixed an intermittent timeout problem that caused writes to -* sometimes get stuck on some machines on some kernels. It turns -* out in these circumstances write_chan() (in n_tty.c) was -* asleep waiting for our wakeup call. Even though we call -* wake_up_interruptible() in digi_write_bulk_callback(), there is -* a race condition that could cause the wakeup to fail: if our -* wake_up_interruptible() call occurs between the time that our -* driver write routine finishes and write_chan() sets current->state -* to TASK_INTERRUPTIBLE, the effect of our wakeup setting the state -* to TASK_RUNNING will be lost and write_chan's subsequent call to -* schedule() will never return (unless it catches a signal). -* This race condition occurs because write_bulk_callback() (and thus -* the wakeup) are called asynchronously from an interrupt, rather than -* from the scheduler. We can avoid the race by calling the wakeup -* from the scheduler queue and that's our fix: Now, at the end of -* write_bulk_callback() we queue up a wakeup call on the scheduler -* task queue. We still also invoke the wakeup directly since that -* squeezes a bit more performance out of the driver, and any lost -* race conditions will get cleaned up at the next scheduler run. -* -* NOTE: The problem also goes away if you comment out -* the two code lines in write_chan() where current->state -* is set to TASK_RUNNING just before calling driver.write() and to -* TASK_INTERRUPTIBLE immediately afterwards. This is why the -* problem did not show up with the 2.2 kernels -- they do not -* include that code. -* -* (5/16/2000) pberger and borchers -* -- Added timeouts to sleeps, to defend against lost wake ups. -* -- Handle transition to/from B0 baud rate in digi_set_termios. -* -* (5/13/2000) pberger and borchers -* -- All commands now sent on out of band port, using -* digi_write_oob_command. -* -- Get modem control signals whenever they change, support TIOCMGET/ -* SET/BIS/BIC ioctls. -* -- digi_set_termios now supports parity, word size, stop bits, and -* receive enable. -* -- Cleaned up open and close, use digi_set_termios and -* digi_write_oob_command to set port parameters. -* -- Added digi_startup_device to start read chains on all ports. -* -- Write buffer is only used when count==1, to be sure put_char can -* write a char (unless the buffer is full). -* -* (5/10/2000) pberger and borchers -* -- Added MOD_INC_USE_COUNT/MOD_DEC_USE_COUNT calls on open/close. -* -- Fixed problem where the first incoming character is lost on -* port opens after the first close on that port. Now we keep -* the read_urb chain open until shutdown. -* -- Added more port conditioning calls in digi_open and digi_close. -* -- Convert port->active to a use count so that we can deal with multiple -* opens and closes properly. -* -- Fixed some problems with the locking code. -* -* (5/3/2000) pberger and borchers -* -- First alpha version of the driver--many known limitations and bugs. -* -* -* Locking and SMP -* -* - Each port, including the out-of-band port, has a lock used to -* serialize all access to the port's private structure. -* - The port lock is also used to serialize all writes and access to -* the port's URB. -* - The port lock is also used for the port write_wait condition -* variable. Holding the port lock will prevent a wake up on the -* port's write_wait; this can be used with cond_wait_... to be sure -* the wake up is not lost in a race when dropping the lock and -* sleeping waiting for the wakeup. -* - digi_write() does not sleep, since it is sometimes called on -* interrupt time. -* - digi_write_bulk_callback() and digi_read_bulk_callback() are -* called directly from interrupts. Hence spin_lock_irqsave() -* and spin_unlock_irqrestore() are used in the rest of the code -* for any locks they acquire. -* - digi_write_bulk_callback() gets the port lock before waking up -* processes sleeping on the port write_wait. It also schedules -* wake ups so they happen from the scheduler, because the tty -* system can miss wake ups from interrupts. -* - All sleeps use a timeout of DIGI_RETRY_TIMEOUT before looping to -* recheck the condition they are sleeping on. This is defensive, -* in case a wake up is lost. -* - Following Documentation/DocBook/kernel-locking.tmpl no spin locks -* are held when calling copy_to/from_user or printk. */ #include <linux/kernel.h> |
