Commit Graph

5 Commits

Author SHA1 Message Date
Joris van Rantwijk
253ca92328 USB: add flow control to usb-serial generic driver.
I added two fields to struct usb_serial_port to keep track of the
throttle state. Other usb-serial drivers typically use private data for
such things, but the generic driver can not really do that because some
of its code is also used by other drivers (which may have their own
private data needs).

As it is, I am not sure that this patch is useful in all scenarios.
It is certainly helpful for low-bandwidth devices that can hold their
data in response to throttling. But for devices that pump data in
real-time as fast as possible (webcam, A/D converter, etc), throttling
may actually cause more data loss.

From: Joris van Rantwijk <jorispubl@xs4all.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-02-16 15:32:18 -08:00
Greg Kroah-Hartman
93bacefc4c USB serial: add dynamic id support to usb-serial core
Thanks to Johannes Hölzl <johannes.hoelzl@gmx.de> for fixing a few
things and getting it all working properly.

This adds support for dynamic usb ids to the usb serial core.  The file
"new_id" will show up under the usb serial driver, not the usb driver
associated with the usb-serial driver (yeah, it can be a bit confusing
at first glance...)

This patch also modifies the USB core to allow the usb-serial core to
reuse much of the dynamic id logic.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Johannes Hölzl <johannes.hoelzl@gmx.de>
2007-02-07 15:44:33 -08:00
Alan Cox
606d099cdd [PATCH] tty: switch to ktermios
This is the grungy swap all the occurrences in the right places patch that
goes with the updates.  At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs

If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.

If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)

Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia

[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Martin Peschke <mp3@de.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-08 08:28:57 -08:00
David Howells
7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
Greg Kroah-Hartman
a969888ce9 [PATCH] USB: move usb-serial.h to include/linux/usb/
USB serial outside of the kernel tree can not build properly due to
usb-serial.h being buried down in the source tree.  This patch moves the
location of the file to include/linux/usb and fixes up all of the usb
serial drivers to handle the move properly.

Cc: Sergei Organov <osv@javad.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-07-12 16:03:25 -07:00