linux-stable.git/drivers/tty/mxser.c, branch v5.14.2

mxser: introduce mxser_16550A_or_MUST helper

2021-06-18T11:10:03+00:00

This check is used in the code on many places. Either in positive or
negative form. So introduce a helper called mxser_16550A_or_MUST for
this purpose. And replace all the occurrences.

This simplifies many ifs in there.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210618061516.662-67-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

mxser: rename flags to old_speed in mxser_set_serial_info

2021-06-18T11:10:03+00:00

Local 'flags' are used to store speed in mxser_set_serial_info, not
actual flags (by doing & ASYNC_SPD_MASK). So rename 'flags' to
'old_speed' (after what it is).

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210618061516.662-66-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

mxser: use port variable in mxser_set_serial_info

2021-06-18T11:10:03+00:00

mxser_set_serial_info already defined a local 'port' of type struct
tty_port. So use it in the code everywhere.

This eliminates some text from the code there.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210618061516.662-65-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

mxser: access info->MCR under info->slock

2021-06-18T11:10:03+00:00

info->MCR is protected by info->slock all over the code. Extend the lock
in mxser_tiocmget around the info->MCR fetch too.

It likely doesn't change anything, but it's always good to be consistent.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210618061516.662-64-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

mxser: fix typos around enhanced mode

2021-06-18T11:10:03+00:00

Fix spelling of "enhanced" in macros and comments around them.

While "enchance" comes from the original Moxa's driver, I don't think it
was meant to be that. From the context, they obviously mean "enhanced".

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210618061516.662-63-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

mxser: decrypt FCR values

2021-06-18T11:10:02+00:00

Currently, some of the values written to FCR are magic constants. But
they are composed of well-defined bits. Use these named macros in place
of the constants.

No changes in objdump -d.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210618061516.662-62-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

mxser: remove xmit_cnt < 0 tests

2021-06-18T11:10:02+00:00

mxser_port::xmit_cnt is unsigned, it cannot be negative. Therefore
remove all the xmit_cnt < 0 tests.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210618061516.662-61-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

mxser: introduce and use start/stop_tx helpers

2021-06-18T11:10:02+00:00

Starting and stopping TX is performed on many places in the driver. It
is repeated outb and info->IER modification.  Create few helpers
(__mxser_start_tx, mxser_start_tx, __mxser_stop_tx) and use them in the
code instead of open coding.

This should be a base for an uart driver for this device in the future.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210618061516.662-60-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

mxser: extract and dedup CTS handling

2021-06-18T11:10:02+00:00

CTS is handled on two locations in mxser. Extract the code into
separation function mxser_handle_cts. And call it from the two
locations.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210618061516.662-59-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman

mxser: don't start TX from tty_operations::put_char

2021-06-18T11:10:02+00:00

TX is not supposed to be started from tty_operations::put_char. Line
disciplines ought to call tty_operations::put_char several times and
then do a single tty_operations::flush_chars to start TX.

Fix this in mxser by removing TX startup from mxser_put_char.

Signed-off-by: Jiri Slaby 
Link: https://lore.kernel.org/r/20210618061516.662-58-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman