USB: ftdi_sio: fix resolution of 2232H baud rate dividers

The 2232H high speed baud rates also support fractional baud rate divisors, but when the performing the divisions before the multiplication, the fractional bits are lost. Signed-off-by: Daniel Glöckner <[email protected]> Acked-by: Mark Adamson <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
yshchan · Jan 23, 2011 · f6c259a · f6c259a
1 parent 9abff15
commit f6c259a
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
@@ -955,7 +955,7 @@ static __u32 ftdi_2232h_baud_base_to_divisor(int baud, int base)
 	int divisor3;
 
 	/* hi-speed baud rate is 10-bit sampling instead of 16-bit */
-	divisor3 = (base / 10 / baud) * 8;
+	divisor3 = base * 8 / (baud * 10);
 
 	divisor = divisor3 >> 3;
 	divisor |= (__u32)divfrac[divisor3 & 0x7] << 14;