When a PCI error is detected, reset code in 8250_pci.c suspends the uart
ports to block IO while recovery procedure is performed. Nevertheless,
TIOCMGET and TIOCMSET ioctls are still able to reach the device even
when it is suspended, which might cause EEH recovery of serial adapters
to fail on Power systems. This patch blocks any TIOCMGET/TIOCMSET calls
from reaching the device if the port is suspended, to avoid racing with
the recovery procedure.
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/serial_core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 603d2cc..e4ecbd2 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -979,7 +979,7 @@ static int uart_tiocmget(struct tty_struct *tty)
int result = -EIO;
mutex_lock(&port->mutex);
- if (!(tty->flags & (1 << TTY_IO_ERROR))) {
+ if (!(tty->flags & (1 << TTY_IO_ERROR)) && !uport->suspended) {
result = uport->mctrl;
spin_lock_irq(&uport->lock);
result |= uport->ops->get_mctrl(uport);
@@ -999,7 +999,7 @@ uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear)
int ret = -EIO;
mutex_lock(&port->mutex);
- if (!(tty->flags & (1 << TTY_IO_ERROR))) {
+ if (!(tty->flags & (1 << TTY_IO_ERROR)) && !uport->suspended) {
uart_update_mctrl(uport, set, clear);
ret = 0;
}
--
2.1.0
--
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