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path: root/drivers/tty/mxser.c
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Diffstat (limited to 'drivers/tty/mxser.c')
-rw-r--r--drivers/tty/mxser.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 1c0c9553bc05..7dd38047ba23 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -246,11 +246,11 @@ struct mxser_port {
unsigned char err_shadow;
struct async_icount icount; /* kernel counters for 4 input interrupts */
- int timeout;
+ unsigned int timeout;
int read_status_mask;
int ignore_status_mask;
- int xmit_fifo_size;
+ unsigned int xmit_fifo_size;
int xmit_head;
int xmit_tail;
int xmit_cnt;
@@ -572,8 +572,9 @@ static void mxser_dtr_rts(struct tty_port *port, int on)
static int mxser_set_baud(struct tty_struct *tty, long newspd)
{
struct mxser_port *info = tty->driver_data;
- int quot = 0, baud;
+ unsigned int quot = 0, baud;
unsigned char cval;
+ u64 timeout;
if (!info->ioaddr)
return -1;
@@ -594,8 +595,13 @@ static int mxser_set_baud(struct tty_struct *tty, long newspd)
quot = 0;
}
- info->timeout = ((info->xmit_fifo_size * HZ * 10 * quot) / info->baud_base);
- info->timeout += HZ / 50; /* Add .02 seconds of slop */
+ /*
+ * worst case (128 * 1000 * 10 * 18432) needs 35 bits, so divide in the
+ * u64 domain
+ */
+ timeout = (u64)info->xmit_fifo_size * HZ * 10 * quot;
+ do_div(timeout, info->baud_base);
+ info->timeout = timeout + HZ / 50; /* Add .02 seconds of slop */
if (quot) {
info->MCR |= UART_MCR_DTR;