@@ -2233,16 +2233,19 @@ static void serial8250_init_mctrl(struct uart_port *port)
serial8250_set_mctrl(port, port->mctrl);
}
-static void serial8250_initialize(struct uart_port *port)
+static void serial8250_iir_txen_test(struct uart_port *port)
{
struct uart_8250_port *up = up_to_u8250p(port);
- unsigned long flags;
bool lsr_TEMT, iir_NOINT;
- serial_port_out(port, UART_LCR, UART_LCR_WLEN8);
+ if (port->quirks & UPQ_NO_TXEN_TEST)
+ return;
- uart_port_lock_irqsave(port, &flags);
- serial8250_init_mctrl(port);
+ /* Do a quick test to see if we receive an interrupt when we enable the TX irq. */
+ serial_port_out(port, UART_IER, UART_IER_THRI);
+ lsr_TEMT = serial_port_in(port, UART_LSR) & UART_LSR_TEMT;
+ iir_NOINT = serial_port_in(port, UART_IIR) & UART_IIR_NO_INT;
+ serial_port_out(port, UART_IER, 0);
/*
* Serial over Lan (SoL) hack:
@@ -2250,26 +2253,30 @@ static void serial8250_initialize(struct uart_port *port)
* Lan. Those chips take a longer time than a normal serial device to signalize that a
* transmission data was queued. Due to that, the above test generally fails. One solution
* would be to delay the reading of iir. However, this is not reliable, since the timeout is
- * variable. So, let's just don't test if we receive TX irq. This way, we'll never enable
- * UART_BUG_TXEN.
+ * variable. So, in case of UPQ_NO_TXEN_TEST, let's just don't test if we receive TX irq.
+ * This way, we'll never enable UART_BUG_TXEN.
*/
- if (!(port->quirks & UPQ_NO_TXEN_TEST)) {
- /* Do a quick test to see if we receive an interrupt when we enable the TX irq. */
- serial_port_out(port, UART_IER, UART_IER_THRI);
- lsr_TEMT = serial_port_in(port, UART_LSR) & UART_LSR_TEMT;
- iir_NOINT = serial_port_in(port, UART_IIR) & UART_IIR_NO_INT;
- serial_port_out(port, UART_IER, 0);
-
- if (lsr_TEMT && iir_NOINT) {
- if (!(up->bugs & UART_BUG_TXEN)) {
- up->bugs |= UART_BUG_TXEN;
- dev_dbg(port->dev, "enabling bad tx status workarounds\n");
- }
- } else {
- up->bugs &= ~UART_BUG_TXEN;
+ if (lsr_TEMT && iir_NOINT) {
+ if (!(up->bugs & UART_BUG_TXEN)) {
+ up->bugs |= UART_BUG_TXEN;
+ dev_dbg(port->dev, "enabling bad tx status workarounds\n");
}
+ return;
}
+ /* FIXME: why is this needed? */
+ up->bugs &= ~UART_BUG_TXEN;
+}
+
+static void serial8250_initialize(struct uart_port *port)
+{
+ unsigned long flags;
+
+ serial_port_out(port, UART_LCR, UART_LCR_WLEN8);
+
+ uart_port_lock_irqsave(port, &flags);
+ serial8250_init_mctrl(port);
+ serial8250_iir_txen_test(port);
uart_port_unlock_irqrestore(port, flags);
}
After commit 795158691cc0 ("serial: 8250: extract serial8250_initialize()"), split serial8250_initialize() even more -- the TX enable test part of this code can be separated into serial8250_iir_txen_test(). Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> --- drivers/tty/serial/8250/8250_port.c | 49 ++++++++++++++++------------- 1 file changed, 28 insertions(+), 21 deletions(-)