FAILED: patch "[PATCH] staging: fwserial: fix TIOCSSERIAL jiffies conversions" failed to apply to 4.9-stable tree

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7a3791afdbd5a951b09a7689bba856bd9f6c6a9f Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Wed, 7 Apr 2021 12:23:19 +0200
Subject: [PATCH] staging: fwserial: fix TIOCSSERIAL jiffies conversions

The port close_delay parameter set by TIOCSSERIAL is specified in jiffies, while the value returned by TIOCGSERIAL is specified in centiseconds.

Add the missing conversions so that TIOCGSERIAL works as expected also when HZ is not 100.

index c368082aae1a..c963848522b1 100644
@@ -1223,7 +1223,7 @@ static int get_serial_info(struct tty_struct *tty,
 	ss->flags = port->port.flags;
 	ss->xmit_fifo_size = FWTTY_PORT_TXFIFO_LEN;
 	ss->baud_base = 400000000;
-	ss->close_delay = port->port.close_delay;
+	ss->close_delay = jiffies_to_msecs(port->port.close_delay) / 10;
 	mutex_unlock(&port->port.mutex);
 	return 0;
 }

@@ -1245,7 +1245,7 @@ static int set_serial_info(struct tty_struct *tty,
 			return -EPERM;
 		}
 	}
-	port->port.close_delay = ss->close_delay * HZ / 100;
+	port->port.close_delay = msecs_to_jiffies(ss->close_delay * 10);
 	mutex_unlock(&port->port.mutex);
 
 	return 0;