ipack/devices/ipoctal: add rx_enable flag

Thus, we don't enable RX when a termios setup has been called, as it could be
disabled previously.

As the control registers (Rx, Tx flags specifically) cannot be read from the
device, we keep this info in rx_enable.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/ipack/devices/ipoctal.c

@@ -43,6 +43,7 @@ struct ipoctal_channel {
 	unsigned int			board_id;
 	u8				isr_rx_rdy_mask;
 	u8				isr_tx_rdy_mask;
+	unsigned int			rx_enable;
 };
 
 struct ipoctal {
@@ -65,6 +66,7 @@ static int ipoctal_port_activate(struct tty_port *port, struct tty_struct *tty)
 	 * there is something to send
 	 */
 	iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
+	channel->rx_enable = 1;
 	return 0;
 }
 
@@ -309,6 +311,7 @@ static int ipoctal_inst_slot(struct ipoctal *ipoctal, unsigned int bus_nr,
 		}
 
 		iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
+		channel->rx_enable = 0;
 		iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
 		iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
 		iowrite8(MR1_CHRL_8_BITS | MR1_ERROR_CHAR | MR1_RxINT_RxRDY,
@@ -430,6 +433,7 @@ static int ipoctal_write_tty(struct tty_struct *tty,
 	/* As the IP-OCTAL 485 only supports half duplex, do it manually */
 	if (channel->board_id == IPACK1_DEVICE_ID_SBS_OCTAL_485) {
 		iowrite8(CR_DISABLE_RX, &channel->regs->w.cr);
+		channel->rx_enable = 0;
 		iowrite8(CR_CMD_ASSERT_RTSN, &channel->regs->w.cr);
 	}
 
@@ -589,8 +593,9 @@ static void ipoctal_set_termios(struct tty_struct *tty,
 	iowrite8(mr2, &channel->regs->w.mr);
 	iowrite8(csr, &channel->regs->w.csr);
 
-	/* Enable again the RX */
-	iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
+	/* Enable again the RX, if it was before */
+	if (channel->rx_enable)
+		iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
 }
 
 static void ipoctal_hangup(struct tty_struct *tty)
@@ -610,6 +615,7 @@ static void ipoctal_hangup(struct tty_struct *tty)
 	tty_port_hangup(&channel->tty_port);
 
 	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
+	channel->rx_enable = 0;
 	iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
 	iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
 	iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);