USB: serial: pl2303: fix xon/xoff flow control

Fix the XON/XOFF flow-control implementation by reporting back the attributes actually supported while ignoring the rest.

Note that only outgoing XON/XOFF flow control (IXON) is currently supported for PL2303HX, and only using the default start and stop chars.

Fixes 68270dab9710 ("USB: serial: pl2303: fix non-supported xon/xoff")

Fixes 7041d9c3f01b ("USB: serial: pl2303: add support for tx xon/xoff flow control")

Signed-off-by Johan Hovold <[email protected]>

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 drivers/usb/serial/pl2303.c | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)