diff options
| author |   Nicholas Piggin <npiggin@gmail.com> | 2018-05-01 00:55:56 +1000 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2018-07-23 20:12:32 +1000 |
| commit | 550ddadcc7580ec2a6c22d4ed04291bc6e2428fb (patch) | |
| tree | 107bfb0355a6943e6765293702828fe109310920 /drivers/tty/hvc | |
| parent | tty: hvc: hvc_poll() may sleep (diff) | |
| download | linux-dev-550ddadcc7580ec2a6c22d4ed04291bc6e2428fb.tar.xz linux-dev-550ddadcc7580ec2a6c22d4ed04291bc6e2428fb.zip | |
tty: hvc: hvc_write() may sleep
Rework the hvc_write loop to drop and re-take the spinlock on each
iteration, add a cond_resched. Don't bother with an initial hvc_push
initially, which makes the logic simpler -- just do a hvc_push on
each time around the loop.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/tty/hvc')
| -rw-r--r-- | drivers/tty/hvc/hvc_console.c | 36 |
1 files changed, 21 insertions, 15 deletions
diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index 2abfc0b15fbb..6131d5084c42 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -493,23 +493,29 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count if (hp->port.count <= 0) return -EIO; - spin_lock_irqsave(&hp->lock, flags); + while (count > 0) { + spin_lock_irqsave(&hp->lock, flags); - /* Push pending writes */ - if (hp->n_outbuf > 0) - hvc_push(hp); - - while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) { - if (rsize > count) - rsize = count; - memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); - count -= rsize; - buf += rsize; - hp->n_outbuf += rsize; - written += rsize; - hvc_push(hp); + rsize = hp->outbuf_size - hp->n_outbuf; + + if (rsize) { + if (rsize > count) + rsize = count; + memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); + count -= rsize; + buf += rsize; + hp->n_outbuf += rsize; + written += rsize; + } + + if (hp->n_outbuf > 0) + hvc_push(hp); + + spin_unlock_irqrestore(&hp->lock, flags); + + if (count) + cond_resched(); } - spin_unlock_irqrestore(&hp->lock, flags); /* * Racy, but harmless, kick thread if there is still pending data. |