The callback is now hooked up for any USB to serial driver that wants
it. We only register the callback if any of the usb-serial structures
want it, this keeps the USB core happy.
Thanks to Alan Stern for the ideas on how to do this.
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I can't remember why I wrote it like this many many years ago, but it's
not needed at all, let's rely on the usb-serial core for this function,
especially as it is being overridden by it anyway.
This lets us make usb_serial_probe() a static function, which it should
be.
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1536) fixes a bug in the USB serial core. Unloading and
reloading a serial driver while a serial device is plugged in causes
errors because of the code in usb_serial_disconnect() that tries to
make sure the port_remove method is called. With the new order of
driver registration introduced in the 3.4 kernel, this is definitely
not the right thing to do (if indeed it ever was).
The patch removes that whole section code, along with the mechanism
for keeping track of each port's registration state, which is no
longer needed. The driver core can handle all that stuff for us.
Note: This has been tested only with one or two USB serial drivers.
In theory, other drivers might still run into trouble. But if they
do, it will be the fault of the drivers, not of this patch -- that is,
the drivers will need to be fixed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that module_driver() can handle varargs, use it instead of rolling
our own version.
Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that Alan Stern has cleaned up the usb serial driver registration,
we have the ability to create a module_usb_serial_driver macro to make
things a bit simpler, like the other *_driver macros created.
But, as we need two functions here, we can't reuse the existing
module_driver() macro, so we need to roll our own.
Here's a patch implementing module_usb_serial_driver() and it converts
the pl2303 driver to use it, showing a nice cleanup.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No one uses them anymore, they should be using the safer
usb_serial_register_drivers() and usb_serial_deregister_drivers()
functions instead.
Thanks to Alan Stern for writing these functions and porting all
in-kernel users to them.
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch (as1522) adds two new routines to the usb-serial core, for
registering and unregistering serial drivers. Instead of registering
the usb_driver and usb_serial_drivers separately, with error checking
for each one, the drivers can all be registered and unregistered by a
single function call. This reduces duplicated code.
More importantly, the new core routines change the order in which the
drivers are registered. Currently the usb-serial drivers are all
registered first and the usb_driver is done last, which leaves a
window for problems. A udev script may quickly add a new dynamic-ID
for a usb-serial driver, causing the corresponding usb_driver to be
probed. If the usb_driver hasn't been registered yet then an oops
will occur.
The new routine prevents such problems by registering the usb_driver
first. To insure that it gets probed properly for already-attached
serial devices, we call driver_attach() after all the usb-serial
drivers have been registered.
Along with adding the new routines, the patch modifies the "generic"
serial driver to use them. Further patches will similarly modify all
the other in-tree USB serial drivers.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add macro which prints an error message only once if port is used a
console.
Reporting errors in a write path when port is used as a console could
otherwise result in an infinite loop.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for multiple read urbs to generic read implementation.
Use a static array of two read urbs for now which is enough to get a
50% throughput increase in one test setup.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Remove no longer used write_urb_busy field from struct usb_serial_port.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (76 commits)
pch_uart: reference clock on CM-iTC
pch_phub: add new device ML7213
n_gsm: fix UIH control byte : P bit should be 0
n_gsm: add a documentation
serial: msm_serial_hs: Add MSM high speed UART driver
tty_audit: fix tty_audit_add_data live lock on audit disabled
tty: move cd1865.h to drivers/staging/tty/
Staging: tty: fix build with epca.c driver
pcmcia: synclink_cs: fix prototype for mgslpc_ioctl()
Staging: generic_serial: fix double locking bug
nozomi: don't use flush_scheduled_work()
tty/serial: Relax the device_type restriction from of_serial
MAINTAINERS: Update HVC file patterns
tty: phase out of ioctl file pointer for tty3270 as well
tty: forgot to remove ipwireless from drivers/char/pcmcia/Makefile
pch_uart: Fix DMA channel miss-setting issue.
pch_uart: fix exclusive access issue
pch_uart: fix auto flow control miss-setting issue
pch_uart: fix uart clock setting issue
pch_uart : Use dev_xxx not pr_xxx
...
Fix up trivial conflicts in drivers/misc/pch_phub.c (same patch applied
twice, then changes to the same area in one branch)
When a driver doesn't know how much data a device is going to send,
the buffer size should be at least as big as the endpoint's maxpacket
value. The serial drivers don't follow this rule; many of them
request only 256-byte bulk-in buffers. As a result, they suffer
overflow errors if a high-speed device wants to send a lot of data,
because high-speed bulk endpoints are required to have a maxpacket
size of 512.
This patch (as1450) fixes the problem by using the driver's
bulk_in_size value as a minimum, always allocating buffers no smaller
than the endpoint's maxpacket size.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Flynn Marquardt <flynn@flynnux.de>
CC: <stable@kernel.org> [after .39-rc1 is out]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We don't use it so we can trim it from here as we try and stamp the file
object dependencies out of the serial code.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Doing tiocmget was such fun we should do tiocmset as well for the same
reasons
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We don't actually need this and it causes problems for internal use of
this functionality. Currently there is a single use of the FILE * pointer.
That is the serial core which uses it to check tty_hung_up_p. However if
that is true then IO_ERROR is also already set so the check may be removed.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Alan's commit 335f8514f2 introduced
.carrier_raised function in several drivers. That also means
tty_port_block_til_ready can now suspend the process trying to open the serial
port when Carrier Detect is low and put it into tty_port.open_wait queue. We
need to wake up the process when Carrier Detect goes high and trigger TTY
hangup when CD goes low.
Some of the devices do not report modem status line changes, or at least we
don't understand the status message, so for those we remove .carrier_raised
again.
Signed-off-by: Libor Pechacek <lpechacek@suse.cz>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Dan Rosenberg noted that various drivers return the struct with uncleared
fields. Instead of spending forever trying to stomp all the drivers that
get it wrong (and every new driver) do the job in one place.
This first patch adds the needed operations and hooks them up, including
the needed USB midlayer and serial core plumbing.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Since handle_sysrq() does not take tty as argument anymore we can
drop it from usb_serial_handle_sysrq_char() as well.
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
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: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg 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: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg 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: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg 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: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
