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Commit 92dfe410 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
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Revert "usb: pl2303: increase the allowed baud rate range for the divisor based encoding method" 



This reverts commit b5c16c6a.

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: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Cc: Frank Schäfer <fschaefer.oss@googlemail.com>
Acked-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e2afb1d6

drivers/usb/serial/pl2303.c

+4 −12
Original line number Diff line number Diff line
@@ -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 */