Commit Graph

31 Commits

Author SHA1 Message Date
Alan Cox 33f0f88f1c [PATCH] TTY layer buffering revamp
The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: John Hawkes <hawkes@sgi.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10 08:01:59 -08:00
Richard Purdie 725a6abfe3 [PATCH] pcmcia: add some IDs for ide-cs and dtl1_cs
Add some PCMCIA device IDs for the microdrive found in the Sharp Zaurus
and a different revision of the Socket CF+ Bluetooth card.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-01-06 00:31:07 +01:00
Dominik Brodowski f8cfa618dc [PATCH] pcmcia: unify attach, EVENT_CARD_INSERTION handlers into one probe callback
Unify the EVENT_CARD_INSERTION and "attach" callbacks to one unified
probe() callback. As all in-kernel drivers are changed to this new
callback, there will be no temporary backwards-compatibility. Inside a
probe() function, each driver _must_ set struct pcmcia_device
*p_dev->instance and instance->handle correctly.

With these patches, the basic driver interface for 16-bit PCMCIA drivers
now has the classic four callbacks known also from other buses:

        int (*probe)            (struct pcmcia_device *dev);
        void (*remove)          (struct pcmcia_device *dev);

        int (*suspend)          (struct pcmcia_device *dev);
        int (*resume)           (struct pcmcia_device *dev);

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-01-06 00:03:24 +01:00
Dominik Brodowski b463581154 [PATCH] pcmcia: remove dev_list from drivers
The linked list of devices managed by each PCMCIA driver is, in very most
cases, unused. Therefore, remove it from many drivers.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-01-06 00:03:20 +01:00
Dominik Brodowski cc3b4866be [PATCH] pcmcia: unify detach, REMOVAL_EVENT handlers into one remove callback
Unify the "detach" and REMOVAL_EVENT handlers to one "remove" function.
Old functionality is preserved, for the moment.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-01-06 00:03:10 +01:00
Dominik Brodowski 98e4c28b7e [PATCH] pcmcia: new suspend core
Move the suspend and resume methods out of the event handler, and into
special functions. Also use these functions for pre- and post-reset, as
almost all drivers already do, and the remaining ones can easily be
converted.

Bugfix to include/pcmcia/ds.c
Signed-off-by: Andrew Morton <akpm@osdl.org>

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2006-01-05 23:59:02 +01:00
Greg Kroah-Hartman 75318d2d7c [PATCH] USB: remove .owner field from struct usb_driver
It is no longer needed, so let's remove it, saving a bit of memory.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-04 13:48:34 -08:00
Marcel Holtmann 1ebb92521d [Bluetooth]: Add endian annotations to the core
This patch adds the endian annotations to the Bluetooth core.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-08 09:57:21 -08:00
Marcel Holtmann 7ef934b3b7 [Bluetooth]: Add another ignore parameter to the HCI USB driver
This patchs adds the module parameter ignore_dga to the HCI USB driver
which makes it possible to prevent this driver from being loaded by
some buggy Digianswer devices.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-11-08 09:57:05 -08:00
Deepak Saxena 089b1dbbde [PATCH] bluetooth: kmalloc + memset -> kzalloc conversion
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 07:54:00 -08:00
Marcel Holtmann 245dc3d19b [Bluetooth] Ignore additional interfaces of BPA 100/105 devices
If a BPA 100/105 device contains more then one interface then ignore the
additional interfaces, because they are unused.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2005-10-28 19:20:57 +02:00
Marcel Holtmann 0372a6627f [Bluetooth] Cleanup of the HCI UART driver
This patch contains the big cleanup of the HCI UART driver. The uneeded
header files are removed and their structure declarations are moved into
the protocol implementations.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2005-10-28 19:20:45 +02:00
Marcel Holtmann 20dd6f59d6 [Bluetooth] Remove TXCRC compile option for BCSP driver
The TXCRC compile option is not really useful and thus change it
into a module parameter.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2005-10-28 19:20:40 +02:00
Al Viro dd0fc66fb3 [PATCH] gfp flags annotations - part 1
- added typedef unsigned int __nocast gfp_t;

 - replaced __nocast uses for gfp flags with gfp_t - it gives exactly
   the same warnings as far as sparse is concerned, doesn't change
   generated code (from gcc point of view we replaced unsigned int with
   typedef) and documents what's going on far better.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-08 15:00:57 -07:00
Marcel Holtmann 0915e8865f [Bluetooth] Add ignore parameters to the HCI USB driver
This patch adds the module parameters ignore_csr and ignore_sniffer
to the HCI USB driver. This allows an easier use of CSR ROM chips
that need an additional initialization routine and the Frontline
sniffers.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2005-09-13 01:32:37 +02:00
Marcel Holtmann 0d48d93947 [Bluetooth]: Move packet type into the SKB control buffer
This patch moves the usage of packet type into the SKB control
buffer. After this patch it is now possible to shrink the sk_buff
structure and redefine its pkt_type.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:55:13 -07:00
Victor Fusco 2eb25a6c34 [Bluetooth]: Fix sparse warnings (__nocast type)
This patch fixes the sparse warnings "implicit cast to nocast type"
for the priority or gfp_mask parameters of the memory allocations.

Signed-off-by: Victor Fusco <victor@cetuc.puc-rio.br>
Signed-off-by: Domen Puncer <domen@coderock.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:55:07 -07:00
Marcel Holtmann 4aa769b997 [Bluetooth]: Update and cleanup of the virtual HCI driver
This patch cleans up the virtual HCI driver. It also adds support for
the dynamic minor device number allocation.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29 15:54:42 -07:00
David S. Miller 8728b834b2 [NET]: Kill skb->list
Remove the "list" member of struct sk_buff, as it is entirely
redundant.  All SKB list removal callers know which list the
SKB is on, so storing this in sk_buff does nothing other than
taking up some space.

Two tricky bits were SCTP, which I took care of, and two ATM
drivers which Francois Romieu <romieu@fr.zoreil.com> fixed
up.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
2005-08-29 15:31:14 -07:00
Marcel Holtmann 66e8b6c31b [Bluetooth] Remove unused functions and cleanup symbol exports
This patch removes the unused bt_dump() function and it also removes
its BT_DMP macro. It also unexports the hci_dev_get(), hci_send_cmd()
and hci_si_event() functions.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2005-08-06 12:36:51 +02:00
Marcel Holtmann e9a3e671c0 [Bluetooth] Kill redundant NULL checks before kfree()
There's no need to check for NULL before calling kfree() on a pointer.

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2005-08-06 12:36:47 +02:00
Marcel Holtmann cad0f6270c [Bluetooth] Send HCI_Reset for Kensington dongle
The Kensington Bluetooth USB adapter is based on a Broadcom chip
with the HID proxy support. To initialize these kind of devices
correctly it is necessary to send HCI_Reset as the first command.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
2005-08-06 12:36:36 +02:00
David S. Miller b03efcfb21 [NET]: Transform skb_queue_len() binary tests into skb_queue_empty()
This is part of the grand scheme to eliminate the qlen
member of skb_queue_head, and subsequently remove the
'list' member of sk_buff.

Most users of skb_queue_len() want to know if the queue is
empty or not, and that's trivially done with skb_queue_empty()
which doesn't use the skb_queue_head->qlen member and instead
uses the queue list emptyness as the test.

Signed-off-by: David S. Miller <davem@davemloft.net>
2005-07-08 14:57:23 -07:00
Dominik Brodowski 44670d2b50 [PATCH] pcmcia: remove references to pcmcia/version.h
As a follow-up, remove the inclusion of pcmcia/version.h in many files.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07 18:24:07 -07:00
Dominik Brodowski 1e212f3645 [PATCH] pcmcia: move event handler
Move the "event handler" to struct pcmcia_driver -- the unified event handler
will disappear really soon, but switching it to struct pcmcia_driver in the
meantime allows for better "step-by-step" patches.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07 18:24:05 -07:00
Dominik Brodowski 88eca2e526 [PATCH] pcmcia: id_table for dtl1_cs.c
Add pcmcia_device_id table.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27 18:03:15 -07:00
Dominik Brodowski 279c936153 [PATCH] pcmcia: id_table for btuart_cs.c
Add pcmcia_device_id table.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27 18:03:15 -07:00
Dominik Brodowski a01c3ed48e [PATCH] pcmcia: id_table for bt3c_cs.c
Add pcmcia_device_id table.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27 18:03:15 -07:00
Dominik Brodowski 7f70cb6d9f [PATCH] pcmcia: id_table for bluecard_cs.c
Add pcmcia_device_id table.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-27 18:03:15 -07:00
Alexey Dobriyan 64ccd715d3 [PATCH] Convert users to tty_unregister_ldisc()
tty_register_ldisc(N_FOO, NULL) => tty_unregister_ldisc(N_FOO)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23 09:45:36 -07:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00