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authorChristophe Leroy <christophe.leroy@c-s.fr>2018-09-14 10:32:50 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-18 15:22:15 +0200
commitbe28c1e3ca29887e207f0cbcd294cefe5074bab6 (patch)
tree91546e6ee9f9c0ef119983ecee1792adc7e64996 /drivers/tty
parent3216c622a24b0ebb9c159a8d1daf7f17a106b3f5 (diff)
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@windriver.com> Cc: <stable@vger.kernel.org> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/cpm_uart/cpm_uart_core.c10
1 files 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--;