Remove multi-urb write from the generic driver and simplify the
prepare_write_buffer prototype:

	int (*prepare_write_buffer)(struct usb_serial_port *port,
						void *dest, size_t size);

The default implementation simply fills dest with data from port write
fifo but drivers can override it if they need to process the outgoing
data (e.g. add headers).

Turn ftdi_sio into a generic fifo-based driver, which lowers CPU usage
significantly for small writes while retaining maximum throughput.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Reimplement fifo-based writes in the generic driver using a multiple
pre-allocated urb scheme.

In contrast to multi-urb writes, no allocations (of urbs or buffers) are
made during run-time and there is less pressure on the host stack
queues as currently only two urbs are used (implementation is generic
and can handle more than two urbs as well, though).

Initial tests using ftdi_sio show that the implementation achieves the
same (maximum) throughput at high baudrates as multi-urb writes. The CPU
usage is much lower than for multi-urb writes for small write requests
and only slightly higher for large (e.g. 2k) requests (due to extra copy
via fifo?).

Also outperforms multi-urb writes for small write requests on an
embedded arm-9 system, where multi-urb writes are CPU-bound at high
baudrates (perf reveals that a lot of time is spent in the host stack
enqueue function -- could perhaps be a bug as well).

Keeping the original write_urb, buffer and flag for now as there are
other drivers depending on them.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Kill circular buffers for tx and rx as well as read work thread, and
switch to generic kfifo-based write implementation.

This is an example of how prepare_write_buffer and process_read_urb can
be used to handle protocols with packet headers.

Please note the diffstat which shows that the same functionality is now
provided using only a tenth of the code (including whitespace and
comments, though).
Tested-by: NNaranjo, Manuel Francisco <naranjo.manuel@gmail.com>
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The original SIO devices require a control byte for every packet
written. Clean up the unnecessarily messy implementation of this.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Switch to the generic, multi-urb, write implementation.

Note that this will also make it fairly easy to use the generic
fifo-based write implementation: simply unset the multi_urb_write flag
and modify prepare_write_buffer (or unset if not using a legacy SIO
device). This may be desirable for instance on an embedded system where
optimal throughput at high baudrates may not be as important as other
factors (e.g. no allocations during runtime and less pressure on host
stack).
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Another CDC-ACM + vendor specific interface layout.
Signed-off-by: NDan Williams <dcbw@redhat.com>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

this patch adds ZTE modem devices
Signed-off-by: NJoey <zhao.ming9@zte.com.cn>
Cc: stable <stable@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

BKL isn't anymore present into this file thus it is no necessary still include smp_lock.h.
Signed-off-by: NAlessio Igor Bogani <abogani@texware.it>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fix mos7720 Kconfig dependencies.
When an enabled bool selects a tristate, the tristate becomes =y,
even if it should be limited to modular, so limit the bool kconfig
option to configs that will build cleanly.
Also change the if-block to a simple depends on.

drivers/built-in.o: In function `mos7720_release':
mos7720.c:(.text+0xad432): undefined reference to `parport_remove_port'
drivers/built-in.o: In function `mos7715_parport_init':
mos7720.c:(.text+0xae197): undefined reference to `parport_register_port'
mos7720.c:(.text+0xae210): undefined reference to `parport_announce_port'
drivers/built-in.o:(.data+0x201c8): undefined reference to `parport_ieee1284_read_nibble'
drivers/built-in.o:(.data+0x201d0): undefined reference to `parport_ieee1284_read_byte'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

No functionality added or bugs fixed, just improved code consistency and
(hopefully) readability by replacing send_mos_cmd with the register read & write
functions that were used for parallel port registers.  Also shortens overall
file length.

Thoroughly tested, with emphasis on regression testing the serial port.
Signed-off-by: NMike Dunn <mikedunn@newsguy.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add support for the parallel port on the moschip MCS7715 device.  The port
registers itself with the parport subsystem as a low-level driver.  A separate
entry to the kernel configuration is added beneath that for the mos7720, to
avoid the need to link with the parport subsystem code for users who don't have
or don't want the parallel port.  Only compatibility mode is currently supported
(no ECP/EPP).  Tested with both moschip devices (7720 and 7715) on UP and SMP
hosts, including regression testing of serial port, concurrent operation of
serial and parallel ports, and various connect / disconnect scenarios.
Signed-off-by: NMike Dunn <mikedunn@newsguy.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add ids for Qualcomm Gobi 2000 QDL and Modem modes. Gobi 2000 has a
single altsetting in QDL mode, so adapt code to handle that.

Firmware upload protocol is also slightly different, with an
additional firmware file. However, qcserial doesn't handle firmware
uploading.

Tested on Lenovo Thinkpad T510.
Signed-off-by: NAnssi Hannula <anssi.hannula@gmail.com>
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Make qcserial use the generic USB wwan code. This should result in a
performance improvement.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

As this code was simply factored out of option, this is a simple
conversion.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The generic USB serial code is ill-suited for high-speed USB wwan devices,
resulting in the option driver. However, other non-option devices may also
gain similar benefits from not using the generic code. Factorise out the
non-option specific code from the option driver and make it available to
other users.
Signed-off-by: NMatthew Garrett <mjg@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

All unsuccessful (non-zero status) URBs were being dropped. After N_IN_URBs are
dropped you will no longer be able to receive data.

This patch resubmits unsuccessful URBs unless the status indicates that it should
be terminated. The statuses that indicate the URB should be terminated was
gathered from other similar drivers.
Signed-off-by: NJames Maki <jamescmaki@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Remove unnecessary comments stating function names at (some)
opening/closing braces.
Fix some whitespace issues.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Generalise write buffer preparation.

This allows for drivers to manipulate (e.g. add headers) to bulk out
data before it is sent.

This adds a new function pointer to usb_serial_driver:

int (*prepare_write_buffer)(struct usb_serial_port *port,
		void **dest, size_t size, const void *src, size_t count);

The function is generic and can be used with either kfifo-based or
multi-urb writes:

If *dest is NULL the implementation should allocate dest.
If src is NULL the implementation should use the port write fifo.

If not set, a generic implementation is used which simply uses memcpy or
kfifo_out.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Use dynamic transfer buffer sizes since it is more efficient to let the
host controller do the partitioning to fit endpoint size. This way we
also do not use more than one urb per write request.

Replace max_in_flight_urbs with multi_urb_write flag in struct
usb_serial_driver to enable multi-urb writes.

Use MAX_TX_URBS=40 and a max buffer size of PAGE_SIZE to prevent DoS
attacks.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Allow drivers to implement their own multi-urb write bulk callbacks as
we do for single urb writes.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Use the generic kfifo-based write implementation rather than allowing up
to 4000 8 byte urbs in the host stack queues.

Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Use usb_serial_generic_close to kill the read and write urbs and to
reset the write fifo.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Replace custom fifo-based write implementation with the generic
kfifo-based one.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Submit write urb if it is not already in use and we have buffered data.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Clean up error messages on usb_submit_urb failure.
Remove debug message on zero-length writes.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Switch to generic read implementation and use process_read_urb to do
device specific processing (handle line status).
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Allow drivers to use the generic throttle and unthrottle implementation.
This makes sense for drivers using the generic read functionality.

Note that drivers need to set these explicitly in order to enable them
(i.e., we do not set them at port probe if not defined).
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Use generic read implementation and use process_read_urb to do device
specific processing (handle line status).
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Add process_read_urb to usb_serial_driver so that a driver can rely on
the generic read (and throttle) mechanism but still do device specific
processing of incoming data (such as adding tty_flags before pushing to
line discipline).

The default generic implementation handles sysrq for consoles but
otherwise simply pushes to tty.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Always process and flush read urb, but only resubmit when not throttled.
The new tty-layer supply plenty of slack so there is really no need to
cache and delay processing of a single urb while throttled.

Note that unthrottle now submits using GFP_KERNEL as we are not in
atomic context (so there is no need to save irq state either).

Note also that the process_read_urb function could be added to
usb_serial_driver should any driver need to do any device specific
processing.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

There is no need to initialise the read urb as this is done at port
probe.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The generic read and write bulk urbs are initialised when allocated in
usb_serial_probe. The only field that needs to be updated after that is
the transfer_buffer_length of the write urb.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Use the already exported function for submitting the read urb associated
with a usb_serial_port.

Make sure it returns the result of usb_submit_urb and rename to the
more descriptive usb_serial_generic_submit_read_urb.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Export usb_serial_generic_close so that drivers can easily kill the read
and write urb and make sure that the write fifo is reset.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Make sure fifo is emptied on close.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

On errors the fifo was reset without any locking. This could race with
write which do kfifo_put and perhaps also chars_in_buffer and write_room.

Every other access to the fifo is protected using the port lock so
better add it to the error path as well.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Make sure chars_in_buffer accounts also for data in host stack queues.

This fixes the problem with tty_wait_until_sent returning too soon at
close which could cause the final write urb to be cancelled.
Reported-by: NPete Zaitcev <zaitcev@redhat.com>
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

The pl2303 requires a bulk-in buffer larger than endpoint size to keep
up at high baudrates without loosing data.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Increase the bulk-out buffer size from 64 to 256 byte.

This gives a significant increase in throughput already at 1Mbaud as well
as lowered CPU usage. The buffer is big enough to keep up also at 3Mbaud
(128b would not suffice).

        64b         256b
921k:   640 KB/s    870 KB/s
3M:     640 KB/s    2520 KB/s
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>