Eric Lee / smarc-fsl-linux-kernel

27 Jun, 2006

1 commit

18 Jun, 2006

1 commit

  • 932ff279a   [NET]: Add netif_tx_lock ... Browse Code »

    Various drivers use xmit_lock internally to synchronise with their
    transmission routines. They do so without setting xmit_lock_owner.
    This is fine as long as netpoll is not in use.

    With netpoll it is possible for deadlocks to occur if xmit_lock_owner
    isn't set. This is because if a printk occurs while xmit_lock is held
    and xmit_lock_owner is not set can cause netpoll to attempt to take
    xmit_lock recursively.

    While it is possible to resolve this by getting netpoll to use
    trylock, it is suboptimal because netpoll's sole objective is to
    maximise the chance of getting the printk out on the wire. So
    delaying or dropping the message is to be avoided as much as possible.

    So the only alternative is to always set xmit_lock_owner. The
    following patch does this by introducing the netif_tx_lock family of
    functions that take care of setting/unsetting xmit_lock_owner.

    I renamed xmit_lock to _xmit_lock to indicate that it should not be
    used directly. I didn't provide irq versions of the netif_tx_lock
    functions since xmit_lock is meant to be a BH-disabling lock.

    This is pretty much a straight text substitution except for a small
    bug fix in winbond. It currently uses
    netif_stop_queue/spin_unlock_wait to stop transmission. This is
    unsafe as an IRQ can potentially wake up the queue. So it is safer to
    use netif_tx_disable.

    The hamradio bits used spin_lock_irq but it is unnecessary as
    xmit_lock must never be taken in an IRQ handler.

    Signed-off-by: Herbert Xu
    Signed-off-by: David S. Miller

    Herbert Xu
     

04 May, 2006

1 commit

26 Mar, 2006

1 commit

  • 8d3b33f67   [PATCH] Remove MODULE_PARM ... Browse Code »

    MODULE_PARM was actually breaking: recent gcc version optimize them out as
    unused. It's time to replace the last users, which are generally in the
    most unloved drivers anyway.

    Signed-off-by: Rusty Russell
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Rusty Russell
     

10 Feb, 2006

1 commit

08 Feb, 2006

1 commit

17 Jan, 2006

1 commit

11 Jan, 2006

1 commit

  • 33f0f88f1   [PATCH] TTY layer buffering revamp ... Browse Code »

    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
    Cc: Paul Fulghum
    Signed-off-by: Hirokazu Takata
    Signed-off-by: Serge Hallyn
    Signed-off-by: Jeff Dike
    Signed-off-by: John Hawkes
    Signed-off-by: Martin Schwidefsky
    Signed-off-by: Adrian Bunk
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Alan Cox
     

10 Jan, 2006

1 commit

08 Jan, 2006

1 commit

06 Nov, 2005

1 commit

29 Oct, 2005

1 commit

20 Oct, 2005

1 commit

  • ab7a435a0   [PATCH] Remove unused header. ... Browse Code »

    mkiss.h has been integrated into mkiss.c earlier.

    Signed-off-by: Ralf Baechle DL5RB

    drivers/net/hamradio/mkiss.h | 62 -------------------------------------------
    1 files changed, 62 deletions(-)
    Signed-off-by: Jeff Garzik

    Ralf Baechle
     

19 Oct, 2005

3 commits

  • 74cfe03f8   [PATCH] Initialize the .owner field the tty_ldisc structure. ... Browse Code »

    If .owner isn't set the module can be unloaded even while still active.

    Signed-off-by: Ralf Baechle DL5RB
    Signed-off-by: Jeff Garzik

    Ralf Baechle
     
  • 5793f4be2   [PATCH] SMACK support for mkiss ... Browse Code »

    SMACK (Stuttgart Modified Amateurradio CRC KISS) is a KISS variant that
    uses CRC16 checksums to secure data transfers between the modem and host.
    It's also used to communicate over a pty to applications such as Wampes.

    Patches for Linux 2.4 by Thomas Osterried DL9SAU, upgraded to the latest
    mkiss 2.6 mkiss driver by me.

    Signed-off-by: Thomas Osterried DL9SAU
    Signed-off-by: Ralf Baechle DL5RB
    Signed-off-by: Jeff Garzik

    Ralf Baechle
     
  • bc0a74386   [PATCH] rcu in bpqether driver. ... Browse Code »

    From Suzanne Wood :

    Clarify RCU implementation in bpqether.c.

    Because bpq_new_device() calls list_add_rcu() and bpq_free_device() calls
    list_del_rcu(), substitute list_for_each_entry_rcu() for
    list_for_each_entry() in bpq_get_ax25_dev() and in bpq_seq_start().

    Add rcu dereference protection in bpq_seq_next().

    The rcu_read_lock()/unlock() in bpq_device_event() are removed because
    netdev event handlers are called with RTNL locking in place.

    FYI: bpq_free_device() calls list_del_rcu() which, per list.h, requires
    synchronize_rcu() which can block or call_rcu() or call_rcu_bh() which
    cannot block. Herbert Xu notes that synchronization is done here by
    unregister_netdevice(). This calls synchronize_net() which in turn uses
    synchronize_rcu().

    Signed-off-by: Ralf Baechle DL5RB
    Signed-off-by: Jeff Garzik

    Ralf Baechle
     

04 Oct, 2005

2 commits

13 Sep, 2005

2 commits

10 Sep, 2005

1 commit

30 Aug, 2005

2 commits

27 Aug, 2005

3 commits

  • 815f62bf7   [PATCH] SMP rewrite of mkiss ... Browse Code »

    Rewrite the mkiss driver to make it SMP-proof following the example of
    6pack.c.

    Signed-off-by: Ralf Baechle DL5RB
    Signed-off-by: Jeff Garzik

    Ralf Baechle
     
  • 214838a21   [PATCH] Fix 6pack setting of MAC address ... Browse Code »

    Don't check type of sax25_family; dev_set_mac_address has already done
    that before and anyway, the type to check against would have been
    ARPHRD_AX25. We only got away because AF_AX25 and ARPHRD_AX25 both happen
    to be defined to the same value.

    Don't check sax25_ndigis either; it's value is insignificant for the
    purpose of setting the MAC address and the check has shown to break
    some application software for no good reason.

    Signed-off-by: Ralf Baechle DL5RB
    Signed-off-by: Jeff Garzik

    Ralf Baechle
     
  • 84a2ea1c2   [PATCH] 6pack Timer initialization ... Browse Code »

    I dropped the timer initialization bits by accident when sending the
    p-persistence fix. This patch gets the driver to work again on halfduplex
    links.

    Signed-off-by: Ralf Baechle DL5RB
    Signed-off-by: Jeff Garzik

    Ralf Baechle
     

11 Aug, 2005

2 commits

31 Jul, 2005

2 commits

  • e064cd7e3   [PATCH] SMP fix for 6pack driver ... Browse Code »

    Drivers really only work well in SMP if they actually can be selected.
    This is a leftover from the time when the 6pack drive only used to be
    a bitrotten variant of the slip driver.

    Signed-off-by: Ralf Baechle DL5RB

    Kconfig | 2 +-
    1 files changed, 1 insertion(+), 1 deletion(-)
    Signed-off-by: Jeff Garzik

    Ralf Baechle
     
  • cd8749b4a   [PATCH] Use time_before in hamradio drivers ... Browse Code »

    Use of time_before() macro, defined at linux/jiffies.h, which deal with
    wrapping correctly and are nicer to read.

    Signed-off-by: Marcelo Feitoza Parisi
    Signed-off-by: Domen Puncer
    Signed-off-by: Ralf Baechle DL5RB

    baycom_epp.c | 3 ++-
    baycom_par.c | 3 ++-
    baycom_ser_fdx.c | 3 ++-
    baycom_ser_hdx.c | 3 ++-
    mkiss.c | 3 ++-
    5 files changed, 10 insertions(+), 5 deletions(-)
    Signed-off-by: Jeff Garzik

    Marcelo Feitoza Parisi
     

09 Jul, 2005

1 commit

  • b03efcfb2   [NET]: Transform skb_queue_len() binary tests into skb_queue_empty() ... Browse Code »

    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

    David S. Miller
     

24 Jun, 2005

1 commit

03 Jun, 2005

1 commit

04 May, 2005

1 commit

25 Apr, 2005

1 commit

17 Apr, 2005

1 commit

  • 1da177e4c   Linux-2.6.12-rc2 ... Browse Code »

    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!

    Linus Torvalds