This is a note to let you know that I've just added the patch titled
serial: cpm_uart: return immediately from console poll
to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-linus branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.
If you have any questions about this process, please let me know.
>From be28c1e3ca29887e207f0cbcd294cefe5074bab6 Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy@xxxxxx>
Date: Fri, 14 Sep 2018 10:32:50 +0000
Subject: serial: cpm_uart: return immediately from console poll
kgdb expects poll function to return immediately and
returning NO_POLL_CHAR when no character is available.
Fixes: f5316b4aea024 ("kgdb,8250,pl011: Return immediately from console poll")
Cc: Jason Wessel <jason.wessel@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/cpm_uart/cpm_uart_core.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/tty/serial/cpm_uart/cpm_uart_core.c b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
index 24a5f05e769b..e5389591bb4f 100644
--- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
@@ -1054,8 +1054,8 @@ static int poll_wait_key(char *obuf, struct uart_cpm_port *pinfo)
/* Get the address of the host memory buffer.
*/
bdp = pinfo->rx_cur;
- while (bdp->cbd_sc & BD_SC_EMPTY)
- ;
+ if (bdp->cbd_sc & BD_SC_EMPTY)
+ return NO_POLL_CHAR;
/* If the buffer address is in the CPM DPRAM, don't
* convert it.
@@ -1090,7 +1090,11 @@ static int cpm_get_poll_char(struct uart_port *port)
poll_chars = 0;
}
if (poll_chars <= 0) {
- poll_chars = poll_wait_key(poll_buf, pinfo);
+ int ret = poll_wait_key(poll_buf, pinfo);
+
+ if (ret == NO_POLL_CHAR)
+ return ret;
+ poll_chars = ret;
pollp = poll_buf;
}
poll_chars--;
--
2.19.0
