diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/serial/pl2303.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c index 09fb55cf3be7..6638c5d9079d 100644 --- a/drivers/usb/serial/pl2303.c +++ b/drivers/usb/serial/pl2303.c @@ -281,6 +281,12 @@ static int pl2303_baudrate_encode_direct(int baud, enum pl2303_type type, 4800, 7200, 9600, 14400, 19200, 28800, 38400, 57600, 115200, 230400, 460800, 614400, 921600, 1228800, 2457600, 3000000, 6000000 }; + /* + * NOTE: The PL2303HX (tested with rev. 3A) also supports the following + * baud rates: 128000, 134400, 161280, 201600, 268800, 403200, 806400. + * As long as we are not using this encoding method for them, there is + * no point in complicating the code to support them. + */ int i; /* Set baudrate to nearest supported value */ @@ -394,6 +400,12 @@ static void pl2303_encode_baudrate(struct tty_struct *tty, * => supported by all chip types * 2) Divisor based method: encodes a divisor to a base value (12MHz*32) * => supported by HX chips (and likely not by type_0/1 chips) + * + * NOTE: Although the divisor based baud rate encoding method is much + * more flexible, some of the standard baud rate values can not be + * realized exactly. But the difference is very small (max. 0.2%) and + * the device likely uses the same baud rate generator for both methods + * so that there is likley no difference. */ if (type != HX) baud = pl2303_baudrate_encode_direct(baud, type, buf); |