lkml.org 
[lkml]   [2012]   [Jun]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 2/6] TTY: um/line, use tty from tty_port
    Date
    From: Jiri Slaby <jslaby@suse.cz>

    This means switching to the tty refcounted model so that we will not
    race with interrupts.

    Signed-off-by: Jiri Slaby <jslaby@suse.cz>
    Cc: Jeff Dike <jdike@addtoit.com>
    Cc: Richard Weinberger <richard@nod.at>
    Cc: user-mode-linux-devel@lists.sourceforge.net
    Signed-off-by: Richard Weinberger <richard@nod.at>
    ---
    arch/um/drivers/chan_kern.c | 4 +++-
    arch/um/drivers/line.c | 25 ++++++++++++++++++-------
    arch/um/drivers/line.h | 1 -
    3 files changed, 21 insertions(+), 9 deletions(-)

    diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
    index 45e248c..87eebfe 100644
    --- a/arch/um/drivers/chan_kern.c
    +++ b/arch/um/drivers/chan_kern.c
    @@ -150,9 +150,11 @@ void chan_enable_winch(struct chan *chan, struct tty_struct *tty)
    static void line_timer_cb(struct work_struct *work)
    {
    struct line *line = container_of(work, struct line, task.work);
    + struct tty_struct *tty = tty_port_tty_get(&line->port);

    if (!line->throttled)
    - chan_interrupt(line, line->tty, line->driver->read_irq);
    + chan_interrupt(line, tty, line->driver->read_irq);
    + tty_kref_put(tty);
    }

    int enable_chan(struct line *line)
    diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
    index 482a7bd..fb6e4ea 100644
    --- a/arch/um/drivers/line.c
    +++ b/arch/um/drivers/line.c
    @@ -19,9 +19,11 @@ static irqreturn_t line_interrupt(int irq, void *data)
    {
    struct chan *chan = data;
    struct line *line = chan->line;
    + struct tty_struct *tty = tty_port_tty_get(&line->port);

    if (line)
    - chan_interrupt(line, line->tty, irq);
    + chan_interrupt(line, tty, irq);
    + tty_kref_put(tty);
    return IRQ_HANDLED;
    }

    @@ -333,7 +335,7 @@ static irqreturn_t line_write_interrupt(int irq, void *data)
    {
    struct chan *chan = data;
    struct line *line = chan->line;
    - struct tty_struct *tty = line->tty;
    + struct tty_struct *tty;
    int err;

    /*
    @@ -352,10 +354,13 @@ static irqreturn_t line_write_interrupt(int irq, void *data)
    }
    spin_unlock(&line->lock);

    + tty = tty_port_tty_get(&line->port);
    if (tty == NULL)
    return IRQ_NONE;

    tty_wakeup(tty);
    + tty_kref_put(tty);
    +
    return IRQ_HANDLED;
    }

    @@ -409,7 +414,7 @@ int line_open(struct line *lines, struct tty_struct *tty)

    BUG_ON(tty->driver_data);
    tty->driver_data = line;
    - line->tty = tty;
    + tty_port_tty_set(&line->port, tty);

    err = enable_chan(line);
    if (err) /* line_close() will be called by our caller */
    @@ -449,7 +454,7 @@ void line_close(struct tty_struct *tty, struct file * filp)
    if (--line->port.count)
    goto out_unlock;

    - line->tty = NULL;
    + tty_port_tty_set(&line->port, NULL);
    tty->driver_data = NULL;

    if (line->sigio) {
    @@ -610,9 +615,15 @@ int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
    mutex_lock(&line->count_lock);
    if (!line->valid)
    CONFIG_CHUNK(str, size, n, "none", 1);
    - else if (line->tty == NULL)
    - CONFIG_CHUNK(str, size, n, line->init_str, 1);
    - else n = chan_config_string(line, str, size, error_out);
    + else {
    + struct tty_struct *tty = tty_port_tty_get(&line->port);
    + if (tty == NULL) {
    + CONFIG_CHUNK(str, size, n, line->init_str, 1);
    + } else {
    + n = chan_config_string(line, str, size, error_out);
    + tty_kref_put(tty);
    + }
    + }
    mutex_unlock(&line->count_lock);

    return n;
    diff --git a/arch/um/drivers/line.h b/arch/um/drivers/line.h
    index 0e06a1f..5b3d4fb 100644
    --- a/arch/um/drivers/line.h
    +++ b/arch/um/drivers/line.h
    @@ -33,7 +33,6 @@ struct line_driver {

    struct line {
    struct tty_port port;
    - struct tty_struct *tty;
    struct mutex count_lock;
    int valid;

    --
    1.7.7.3


    \
     
     \ /
      Last update: 2012-06-04 23:01    [W:0.027 / U:1.224 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site