atmel_serial: fix break handling

The RXBRK field in the AT91/AT32 USART status register has the
following definition according to e.g. the AT32AP7000 data sheet:

    RXBRK: Break Received/End of Break
    0: No Break received or End of Break detected since the last RSTSTA.
    1: Break Received or End of Break detected since the last RSTSTA.

Thus, for each break, the USART sets the RXBRK bit twice. This patch
modifies the driver to report the break event to the serial core only
once by keeping track of whether a break condition is currently
active. The break_active flag is reset as soon as a character is
received, so even if we miss the start-of-break interrupt this should
do the right thing.

Signed-off-by: Haavard Skinnemoen <[email protected]>
Cc: Andrew Victor <[email protected]>
Cc: Russell King <[email protected]>
Cc: Ivan Kuten <[email protected]>
Cc: Nicolas Ferre <[email protected]>
Cc: Patrice Vilchez <[email protected]>
Cc: Andrew Morton <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions