On Fri, Apr 19, 2024 at 02:19:47PM +1000, Stephen Rothwell wrote:
> Hi all,
>
> Today's linux-next merge of the tty tree got a conflict in:
>
> drivers/tty/serial/serial_core.c
>
> between commit:
>
> 9cf7ea2eeb74 ("serial: core: Clearing the circular buffer before NULLifying it")
>
> from the tty.current tree and commits:
>
> 1788cf6a91d9 ("tty: serial: switch from circ_buf to kfifo")
> abcd8632f26b ("serial: core: Extract uart_alloc_xmit_buf() and uart_free_xmit_buf()")
>
> from the tty tree.
>
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging. You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
>
> --
> Cheers,
> Stephen Rothwell
>
> diff --cc drivers/tty/serial/serial_core.c
> index c476d884356d,b9d631037ff6..000000000000
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@@ -285,6 -273,53 +273,54 @@@ static int uart_alloc_xmit_buf(struct t
> free_page(page);
> }
>
> + return 0;
> + }
> +
> + static void uart_free_xmit_buf(struct tty_port *port)
> + {
> + struct uart_state *state = container_of(port, struct uart_state, port);
> + struct uart_port *uport;
> + unsigned long flags;
> + char *xmit_buf;
> +
> + /*
> + * Do not free() the transmit buffer page under the port lock since
> + * this can create various circular locking scenarios. For instance,
> + * console driver may need to allocate/free a debug object, which
> + * can end up in printk() recursion.
> + */
> + uport = uart_port_lock(state, flags);
> ++ kfifo_reset(&state->port.xmit_fifo);
> + xmit_buf = port->xmit_buf;
> + port->xmit_buf = NULL;
> + INIT_KFIFO(port->xmit_fifo);
The INIT_KFIFO() call here does the same (same plus more) than the
kfifo_reset() call does, so I'll just drop the kfifo_reset() here and
all should be fine. I'll do this in my tree now, thanks.
greg k-h
