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);
+ uart_port_unlock(uport, flags);
+
+ free_page((unsigned long)xmit_buf);
+ }
+
+ /*
+ * Startup the port. This will be called once per open. All calls
+ * will be serialised by the per-port mutex.
+ */
+ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
+ bool init_hw)
+ {
+ struct uart_port *uport = uart_port_check(state);
+ int retval;
+
+ if (uport->type == PORT_UNKNOWN)
+ return 1;
+
+ /*
+ * Make sure the device is in D0 state.
+ */
+ uart_change_pm(state, UART_PM_STATE_ON);
+
+ retval = uart_alloc_xmit_buf(&state->port);
+ if (retval)
+ return retval;
+
retval = uport->ops->startup(uport);
if (retval == 0) {
if (uart_console(uport) && uport->cons->cflag) {
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.
Looks good, thanks!
greg k-h
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