diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2015-07-13 04:11:31 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-07-24 03:48:43 +0300 |
| commit | ee3ad90be5ec5e94a45aac597a23b1050cd4f1b0 (patch) | |
| tree | 87d65fc6f5dbf48384588b8df4842aad42080364 | |
| parent | 45c6df4471edf5404463756df1014fe7e36db3d3 (diff) | |
| download | linux-ee3ad90be5ec5e94a45aac597a23b1050cd4f1b0.tar.xz | |
serial: 8250: Defer interrupt enable until fifos enabled
An already-active sender can swamp the interrupt handler with
"too much work" if the rx interrupts are enabled when the fifo is
disabled and operating in single-byte mode.
Defer rx and line status interrupt enable until after the fifos
are enabled in set_termios(), but at least initialize the shadow
IER value with the interrupts which will be enabled.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 4dc143eee086..de6655d50c37 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -2002,12 +2002,11 @@ dont_test_tx_en: } /* - * Finally, enable interrupts. Note: Modem status interrupts - * are set via set_termios(), which will be occurring imminently - * anyway, so we don't enable them here. + * Set the IER shadow for rx interrupts but defer actual interrupt + * enable until after the FIFOs are enabled; otherwise, an already- + * active sender can swamp the interrupt handler with "too much work". */ up->ier = UART_IER_RLSI | UART_IER_RDI; - serial_port_out(port, UART_IER, up->ier); if (port->flags & UPF_FOURPORT) { unsigned int icp; |