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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-11-01 17:18:47 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-11-01 17:18:47 +0100 |
| commit | 92dfe410880b8bde731ca1a6e7da2dd3b13404e6 (patch) | |
| tree | 898b579d15acca3bba5b7ecb091a3531c277bbfc /drivers/usb | |
| parent | Revert "usb: pl2303: also use the divisor based baud rate encoding method for... (diff) | |
| download | linux-92dfe410880b8bde731ca1a6e7da2dd3b13404e6.tar.xz linux-92dfe410880b8bde731ca1a6e7da2dd3b13404e6.zip | |
Revert "usb: pl2303: increase the allowed baud rate range for the divisor based encoding method"
This reverts commit b5c16c6a031c52cc4b7dda6c3de46462fbc92eab.
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>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/serial/pl2303.c | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c index 61c9f9d28ee9..693ed7e4871a 100644 --- a/drivers/usb/serial/pl2303.c +++ b/drivers/usb/serial/pl2303.c @@ -324,20 +324,12 @@ static int pl2303_baudrate_encode_divisor(int baud, enum pl2303_type type, */ unsigned int A, B; - /* - * NOTE: The Windows driver allows maximum baud rates of 110% of the - * specified maximium value. - * Quick tests with early (2004) HX (rev. A) chips suggest, that even - * higher baud rates (up to the maximum of 24M baud !) are working fine, - * but that should really be tested carefully in "real life" scenarios - * before removing the upper limit completely. - * Baud rates smaller than the specified 75 baud are definitely working - * fine. - */ + /* Respect the specified baud rate limits */ + baud = max_t(int, baud, 75); if (type == HX) - baud = min_t(int, baud, 6000000 * 1.1); + baud = min_t(int, baud, 6000000); else - baud = min_t(int, baud, 1228800 * 1.1); + baud = min_t(int, baud, 1228800); /* Determine factors A and B */ A = 0; B = 12000000 * 32 / baud; /* 12MHz */ |