Revert "usb: pl2303: do not round to the next nearest standard baud rate for the...

This reverts commit 75417d9f99f89ab241de69d7db15af5842b488c4.

Revert all of the pl2303 changes that went into 3.12-rc1 and -rc2 as
they cause regressions on some versions of the chip.  This will all be
revisited for later kernel versions when we can figure out how to handle
this in a way that does not break working devices.

Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index 04390dff926ada7c495aa37432c19be49ae3492f..b93b3b30dec592658b650e5542bfdba08e476398 100644 (file)
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -273,46 +273,44 @@ static void pl2303_encode_baudrate(struct tty_struct *tty,
                                        struct usb_serial_port *port,
                                        u8 buf[4])
 {
+       const int baud_sup[] = { 75, 150, 300, 600, 1200, 1800, 2400, 3600,
+                                4800, 7200, 9600, 14400, 19200, 28800, 38400,
+                                57600, 115200, 230400, 460800, 500000, 614400,
+                                921600, 1228800, 2457600, 3000000, 6000000 };
+
        struct usb_serial *serial = port->serial;
        struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
        int baud;
+       int i;
 
+       /*
+        * NOTE: Only the values defined in baud_sup are supported!
+        *       => if unsupported values are set, the PL2303 seems to use
+        *          9600 baud (at least my PL2303X always does)
+        */
        baud = tty_get_baud_rate(tty);
        dev_dbg(&port->dev, "baud requested = %d\n", baud);
        if (!baud)
                return;
 
-       if (spriv->type != HX || baud <= 115200) {
-               /*
-                * NOTE: Only the values defined in baud_sup are supported !
-                *       => if unsupported values are set, the PL2303 seems to
-                *          use 9600 baud (at least my PL2303X always does)
-                */
-               const int baud_sup[] = { 75, 150, 300, 600, 1200, 1800, 2400,
-                                        3600, 4800, 7200, 9600, 14400, 19200,
-                                        28800, 38400, 57600, 115200, 230400,
-                                        460800, 500000, 614400, 921600,
-                                        1228800, 2457600, 3000000, 6000000 };
-               int i;
-
-               /* Set baudrate to nearest supported value */
-               for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
-                       if (baud_sup[i] > baud)
-                               break;
-               }
+       /* Set baudrate to nearest supported value */
+       for (i = 0; i < ARRAY_SIZE(baud_sup); ++i) {
+               if (baud_sup[i] > baud)
+                       break;
+       }
 
-               if (i == ARRAY_SIZE(baud_sup))
-                       baud = baud_sup[i - 1];
-               else if (i > 0
-                            && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
-                       baud = baud_sup[i - 1];
-               else
-                       baud = baud_sup[i];
+       if (i == ARRAY_SIZE(baud_sup))
+               baud = baud_sup[i - 1];
+       else if (i > 0 && (baud_sup[i] - baud) > (baud - baud_sup[i - 1]))
+               baud = baud_sup[i - 1];
+       else
+               baud = baud_sup[i];
 
-               /* type_0, type_1 only support up to 1228800 baud */
-               if (spriv->type != HX)
-                       baud = min_t(int, baud, 1228800);
+       /* type_0, type_1 only support up to 1228800 baud */
+       if (spriv->type != HX)
+               baud = min_t(int, baud, 1228800);
 
+       if (spriv->type != HX || baud <= 115200) {
                /* Direct (standard) baud rate encoding method */
                put_unaligned_le32(baud, buf);
        } else {
@@ -333,17 +331,10 @@ static void pl2303_encode_baudrate(struct tty_struct *tty,
                 * => 8 < B < 16: device seems to work not properly
                 * => B <= 8: device uses the max. value B = 512 instead
                 */
-               unsigned int A, B;
 
-               /* Respect the specified baud rate limits */
-               baud = max_t(int, baud, 75);
-               if (spriv->type == HX)
-                       baud = min_t(int, baud, 6000000);
-               else
-                       baud = min_t(int, baud, 1228800);
                /* Determine factors A and B */
-               A = 0;
-               B = 12000000 * 32 / baud;  /* 12MHz */
+               unsigned int A = 0;
+               unsigned int B = 12000000 * 32 / baud;  /* 12MHz */
                B <<= 1; /* Add one bit for rounding */
                while (B > (512 << 1) && A <= 14) {
                        A += 2;