serial: core: Add serial_base_match_and_update_preferred_console()

Let's add serial_base_match_and_update_preferred_console() for consoles
using DEVNAME:0.0 style naming.

The earlier approach to ad

serial: core: Add serial_base_match_and_update_preferred_console()

Let's add serial_base_match_and_update_preferred_console() for consoles
using DEVNAME:0.0 style naming.

The earlier approach to add it caused issues in the kernel command line
ordering as we were calling __add_preferred_console() again for the
deferred consoles.

Signed-off-by: Tony Lindgren <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Tested-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

Revert "serial: core: Add support for DEVNAME:0.0 style naming for kernel console"

This reverts commit 787a1cabac01c99846070fcf702e53befaf89f79.

Let's roll back all of the serial core and printk co

Revert "serial: core: Add support for DEVNAME:0.0 style naming for kernel console"

This reverts commit 787a1cabac01c99846070fcf702e53befaf89f79.

Let's roll back all of the serial core and printk console changes that
went into 6.10-rc1 as there still are problems with them that need to be
sorted out.

Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1
Reported-by: Petr Mladek <[email protected]>
Reported-by: Tony Lindgren <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: John Ogness <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Ilpo Järvinen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

Revert "serial: 8250: Add preferred console in serial8250_isa_init_ports()"

This reverts commit a8b04cfe7dad84e65df5996e14b435fd356fe62c.

Let's roll back all of the serial core and printk console c

Revert "serial: 8250: Add preferred console in serial8250_isa_init_ports()"

This reverts commit a8b04cfe7dad84e65df5996e14b435fd356fe62c.

Let's roll back all of the serial core and printk console changes that
went into 6.10-rc1 as there still are problems with them that need to be
sorted out.

Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1
Reported-by: Petr Mladek <[email protected]>
Reported-by: Tony Lindgren <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: John Ogness <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Ilpo Järvinen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

Revert "serial: 8250: Fix add preferred console for serial8250_isa_init_ports()"

This reverts commit 4547cd76f08a6f301f6ad563f5d0e4566924ec6b.

Let's roll back all of the serial core and printk cons

Revert "serial: 8250: Fix add preferred console for serial8250_isa_init_ports()"

This reverts commit 4547cd76f08a6f301f6ad563f5d0e4566924ec6b.

Let's roll back all of the serial core and printk console changes that
went into 6.10-rc1 as there still are problems with them that need to be
sorted out.

Link: https://lore.kernel.org/r/ZnpRozsdw6zbjqze@tlindgre-MOBL1
Reported-by: Petr Mladek <[email protected]>
Reported-by: Tony Lindgren <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: John Ogness <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Ilpo Järvinen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

serial: core: Fix missing shutdown and startup for serial base port

We are seeing start_tx being called after port shutdown as noted by Jiri.
This happens because we are missing the startup and shut

serial: core: Fix missing shutdown and startup for serial base port

We are seeing start_tx being called after port shutdown as noted by Jiri.
This happens because we are missing the startup and shutdown related
functions for the serial base port.

Let's fix the issue by adding startup and shutdown functions for the
serial base port to block tx flushing for the serial base port when the
port is not in use.

Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM")
Cc: stable <[email protected]>
Reported-by: Jiri Slaby <[email protected]>
Signed-off-by: Tony Lindgren <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

serial: 8250: Fix add preferred console for serial8250_isa_init_ports()

We need to inline serial_base_add_isa_preferred_console() based on
CONFIG_SERIAL_8250_CONSOLE and not based on CONFIG_SERIAL_

serial: 8250: Fix add preferred console for serial8250_isa_init_ports()

We need to inline serial_base_add_isa_preferred_console() based on
CONFIG_SERIAL_8250_CONSOLE and not based on CONFIG_SERIAL_CORE_CONSOLE.
Otherwise we can get the follwoing error as noted by Stephen:

ERROR: modpost: "serial_base_add_isa_preferred_console"
[drivers/tty/serial/8250/8250.ko] undefined!

We also have a duplicate inlined serial_base_add_isa_preferred_console(),
in serial_base_bus.c added by the same commit by accident, let's drop it.

Fixes: a8b04cfe7dad ("serial: 8250: Add preferred console in serial8250_isa_init_ports()")
Reported-by: Stephen Rothwell <[email protected]>
Signed-off-by: Tony Lindgren <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

serial: 8250: Add preferred console in serial8250_isa_init_ports()

Prepare 8250 ISA ports to drop kernel command line serial console
handling from console_setup().

We need to set the preferred cons

serial: 8250: Add preferred console in serial8250_isa_init_ports()

Prepare 8250 ISA ports to drop kernel command line serial console
handling from console_setup().

We need to set the preferred console in serial8250_isa_init_ports()
to drop a dependency to setup_console() handling the ttyS related
quirks. Otherwise when console_setup() handles the ttyS related
options, console gets enabled only at driver probe time.

Note that this mostly affects x86 as this happens based on define
SERIAL_PORT_DFNS.

Signed-off-by: Tony Lindgren <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

serial: core: Add support for DEVNAME:0.0 style naming for kernel console

We can now add hardware based addressing for serial ports. Starting with
commit 84a9582fd203 ("serial: core: Start managing

serial: core: Add support for DEVNAME:0.0 style naming for kernel console

We can now add hardware based addressing for serial ports. Starting with
commit 84a9582fd203 ("serial: core: Start managing serial controllers to
enable runtime PM"), and all the related fixes to this commit, the serial
core now knows to which serial port controller the ports are connected.

The serial ports can be addressed with DEVNAME:0.0 style naming. The names
are something like 00:04:0.0 for a serial port on qemu, and something like
2800000.serial:0.0 on platform device using systems like ARM64 for example.

The DEVNAME is the unique serial port hardware controller device name, AKA
the name for port->dev. The 0.0 are the serial core controller id and port
id.

Typically 0.0 are used for each controller and port instance unless the
serial port hardware controller has multiple controllers or ports.

Using DEVNAME:0.0 style naming actually solves two long term issues for
addressing the serial ports:

1. According to Andy Shevchenko, using DEVNAME:0.0 style naming fixes an
issue where depending on the BIOS settings, the kernel serial port ttyS
instance number may change if HSUART is enabled

2. Device tree using architectures no longer necessarily need to specify
aliases to find a specific serial port, and we can just allocate the
ttyS instance numbers dynamically in whatever probe order

To do this, let's match the hardware addressing style console name to
the character device name used, and add a preferred console using the
character device name.

Note that when using console=DEVNAME:0.0 style kernel command line, the
8250 serial console gets enabled later compared to using console=ttyS
naming for ISA ports. This is because the serial port DEVNAME to character
device mapping is not known until the serial driver probe time. If used
together with earlycon, this issue is avoided.

Signed-off-by: Tony Lindgren <[email protected]>
Reviewed-by: Dhruva Gole <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

serial: core: Fix serial core port id, including multiport devices

We want to fix the serial core port DEVNAME to use a port id of the
hardware specific controller port instance instead of the port-

serial: core: Fix serial core port id, including multiport devices

We want to fix the serial core port DEVNAME to use a port id of the
hardware specific controller port instance instead of the port->line.

For example, the 8250 driver sets up a number of serial8250 ports
initially that can be inherited by the hardware specific driver. At that
the port->line no longer decribes the port's relation to the serial core
controller instance.

Let's fix the issue by assigning port->port_id for each serial core
controller port instance.

Fixes: 7d695d83767c ("serial: core: Fix serial_base_match() after fixing controller port name")
Tested-by: Guenter Roeck <[email protected]>
Reviewed-by: Dhruva Gole <[email protected]>
Signed-off-by: Tony Lindgren <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...

serial: core: Start managing serial controllers to enable runtime PM

We want to enable runtime PM for serial port device drivers in a generic
way. To do this, we want to have the serial core layer m

serial: core: Start managing serial controllers to enable runtime PM

We want to enable runtime PM for serial port device drivers in a generic
way. To do this, we want to have the serial core layer manage the
registered physical serial controller devices.

To manage serial controllers, let's set up a struct bus and struct device
for the serial core controller as suggested by Greg and Jiri. The serial
core controller devices are children of the physical serial port device.
The serial core controller device is needed to support multiple different
kind of ports connected to single physical serial port device.

Let's also set up a struct device for the serial core port. The serial
core port instances are children of the serial core controller device.

With the serial core port device we can now flush pending TX on the
runtime PM resume as suggested by Johan.

Suggested-by: Andy Shevchenko <[email protected]>
Suggested-by: Greg Kroah-Hartman <[email protected]>
Suggested-by: Jiri Slaby <[email protected]>
Suggested-by: Johan Hovold <[email protected]>
Signed-off-by: Tony Lindgren <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

show more ...