On 12/08/2013 08:01 PM, Greg Kroah-Hartman wrote:
On Fri, Nov 22, 2013 at 12:09:58PM -0500, Peter Hurley wrote:tty flip buffers use GFP_ATOMIC allocations for received data which is to be processed by the line discipline. For each byte received, an extra byte is used to indicate the error status of that byte. Instead, if the received data is error-free, encode the entire buffer without status bytes. Signed-off-by: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> --- drivers/tty/tty_buffer.c | 45 +++++++++++++++++++++++++++++++++++---------- include/linux/tty.h | 4 ++++ include/linux/tty_flip.h | 8 ++++++-- 3 files changed, 45 insertions(+), 12 deletions(-) diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index 6a3620e..c4fe20e 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -100,6 +100,7 @@ static void tty_buffer_reset(struct tty_buffer *p, size_t size) p->next = NULL; p->commit = 0; p->read = 0; + p->flags = 0; } /** @@ -230,31 +231,49 @@ void tty_buffer_flush(struct tty_struct *tty) * tty_buffer_request_room - grow tty buffer if needed * @tty: tty structure * @size: size desired + * @flags: buffer flags if new buffer allocated (default = 0) * * Make at least size bytes of linear space available for the tty * buffer. If we fail return the size we managed to find. + * + * Will change over to a new buffer if the current buffer is encoded as + * TTY_NORMAL (so has no flags buffer) and the new buffer requires + * a flags buffer. */ -int tty_buffer_request_room(struct tty_port *port, size_t size) +int __tty_buffer_request_room(struct tty_port *port, size_t size, int flags) { struct tty_bufhead *buf = &port->buf; struct tty_buffer *b, *n; - int left; + int left, change; b = buf->tail; - left = b->size - b->used; + if (b->flags & TTYB_NORMAL) + left = 2 * b->size - b->used; + else + left = b->size - b->used; - if (left < size) { + change = (b->flags & TTYB_NORMAL) && (~flags & TTYB_NORMAL); + if (change || left < size) { /* This is the slow path - looking for new buffers to use */ if ((n = tty_buffer_alloc(port, size)) != NULL) { + n->flags = flags; buf->tail = n; b->commit = b->used; smp_mb(); b->next = n; - } else + } else if (change) + size = 0; + else size = left; } return size; } +EXPORT_SYMBOL_GPL(__tty_buffer_request_room);Why are you exporting this? There is no function prototype anywhere, so no one can even try to call it, it should just be static, right?
Yes, sorry. Thanks for catching this.
I've applied the first 4 patches in this series, care to fix this one up?
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