tty: serial: msm: Don't read off end of tx fifo

For dm uarts in pio mode tx data is transferred to the fifo register 4
bytes at a time, but care is not taken when these 4 bytes spans the end
of the xmit buffer so the loop might read up to 3 bytes past the buffer
and then skip the actual data at the beginning of the buffer.

Fix this by, analogous to the DMA case, make sure the chunk doesn't
wrap the xmit buffer.

Fixes: 3a878c430fd6 ("tty: serial: msm: Add TX DMA support")
Cc: Ivan Ivanov <[email protected]>
Cc: [email protected]
Reported-by: Frank Rowand <[email protected]>
Reported-by: Nicolas Dechesne <[email protected]>
Signed-off-by: Bjorn Andersson <[email protected]>
Acked-by: Andy Gross <[email protected]>
Tested-by: Frank Rowand <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

0 files changed, 0 insertions, 0 deletions