diff options
| author | Jiri Slaby (SUSE) <jirislaby@kernel.org> | 2023-08-16 13:55:30 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-08-22 15:58:16 +0300 |
| commit | ebee41c8490aeb3ef2e7d25f5e97ce45c996da4d (patch) | |
| tree | 18728900e1ad44334b57aa7d0e087b2b981da5c4 /drivers/tty | |
| parent | 035197c908b57804b9407cf119d2c2fe5934ee00 (diff) | |
| download | linux-ebee41c8490aeb3ef2e7d25f5e97ce45c996da4d.tar.xz | |
tty: tty_buffer: invert conditions in __tty_buffer_request_room()
We are used to handle "bad" states in the 'if's in the kernel. Refactor
(invert the two conditions in) __tty_buffer_request_room(), so that the
code returns from the fast paths immediately instead of postponing to
the heavy end of the function.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20230816105530.3335-11-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/tty_buffer.c | 44 |
1 files changed, 22 insertions, 22 deletions
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c index 44c0adaec850..5f6d0cf67571 100644 --- a/drivers/tty/tty_buffer.c +++ b/drivers/tty/tty_buffer.c @@ -266,28 +266,28 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size, size_t left = (b->flags ? 1 : 2) * b->size - b->used; bool change = !b->flags && flags; - if (change || left < size) { - /* This is the slow path - looking for new buffers to use */ - n = tty_buffer_alloc(port, size); - if (n != NULL) { - n->flags = flags; - buf->tail = n; - /* - * Paired w/ acquire in flush_to_ldisc() and lookahead_bufs() - * ensures they see all buffer data. - */ - smp_store_release(&b->commit, b->used); - /* - * Paired w/ acquire in flush_to_ldisc() and lookahead_bufs() - * ensures the latest commit value can be read before the head - * is advanced to the next buffer. - */ - smp_store_release(&b->next, n); - } else if (change) - size = 0; - else - size = left; - } + if (!change && left >= size) + return size; + + /* This is the slow path - looking for new buffers to use */ + n = tty_buffer_alloc(port, size); + if (n == NULL) + return change ? 0 : left; + + n->flags = flags; + buf->tail = n; + /* + * Paired w/ acquire in flush_to_ldisc() and lookahead_bufs() + * ensures they see all buffer data. + */ + smp_store_release(&b->commit, b->used); + /* + * Paired w/ acquire in flush_to_ldisc() and lookahead_bufs() + * ensures the latest commit value can be read before the head + * is advanced to the next buffer. + */ + smp_store_release(&b->next, n); + return size; } |