usb: acm: fix the computation of the number of data bits

The current code assumes that CSIZE is 0000060, which appears to be
wrong on some arches (such as powerpc).

Signed-off-by: Nicolas Boullis <nboullis@debian.org>
Acked-by: Oliver Neukum <oneukum@suse.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 15 insertions, 5 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 572f4e7bd3ff..6e49ec6f3adc 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -817,10 +817,6 @@ static const __u32 acm_tty_speed[] = {
         2500000, 3000000, 3500000, 4000000
 };
 
-static const __u8 acm_tty_size[] = {
-        5, 6, 7, 8
-};
-
 static void acm_tty_set_termios(struct tty_struct *tty,
                                                 struct ktermios *termios_old)
 {
@@ -834,7 +830,21 @@ static void acm_tty_set_termios(struct tty_struct *tty,
         newline.bParityType = termios->c_cflag & PARENB ?
                                 (termios->c_cflag & PARODD ? 1 : 2) +
                                 (termios->c_cflag & CMSPAR ? 2 : 0) : 0;
-        newline.bDataBits = acm_tty_size[(termios->c_cflag & CSIZE) >> 4];
+        switch (termios->c_cflag & CSIZE) {
+        case CS5:
+                newline.bDataBits = 5;
+                break;
+        case CS6:
+                newline.bDataBits = 6;
+                break;
+        case CS7:
+                newline.bDataBits = 7;
+                break;
+        case CS8:
+        default:
+                newline.bDataBits = 8;
+                break;
+        }
         /* FIXME: Needs to clear unsupported bits in the termios */
         acm->clocal = ((termios->c_cflag & CLOCAL) != 0);