serial: sc16is7xx: remove useless enable of enhanced features

commit 1c05bf6 upstream.

Commit 43c51bb ("sc16is7xx: make sure device is in suspend once
probed") permanently enabled access to the enhanced features in
sc16is7xx_probe(), and it is never disabled after that.

Therefore, remove re-enable of enhanced features in
sc16is7xx_set_baud(). This eliminates a potential useless read + write
cycle each time the baud rate is reconfigured.

Fixes: 43c51bb ("sc16is7xx: make sure device is in suspend once probed")
Cc: stable <[email protected]>
Signed-off-by: Hugo Villeneuve <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: hvilleneuvedoo

drivers/tty/serial/sc16is7xx.c

@@ -585,13 +585,6 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
 		div /= prescaler;
 	}
 
-	/* Enable enhanced features */
-	sc16is7xx_efr_lock(port);
-	sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
-			      SC16IS7XX_EFR_ENABLE_BIT,
-			      SC16IS7XX_EFR_ENABLE_BIT);
-	sc16is7xx_efr_unlock(port);
-
 	/* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */
 	sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
 			      SC16IS7XX_MCR_CLKSEL_BIT,