[PATCH 00/29] tty: cleanup no. 99

[PATCH 00/29] tty: cleanup no. 99

[Jiri Slaby (SUSE)]

Hi,

this is (again) a series of cleanup in tty. I am trying to rework
tty+serial to avoid limitations of devices (so called NR_UART or
tty_alloc_driver()'s first parameter). And the below popped up while
crawling through the code. So this is only a prep cleanup.

* many tty flags are now enums
* many functions were improved for readability
* quite a few unused or old code dropped

In particular, the runtime behaviour of the kernel before and after the
changes is supposed to be bug to bug compatible (except moxa's ioctl
and ISA evils dropped). That is, noone should notice.

Cc: Alex Elder <elder@kernel.org>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: greybus-dev@lists.linaro.org
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Johan Hovold <johan@kernel.org>
Cc: linux-alpha@vger.kernel.org
Cc: linux-staging@lists.linux.dev
Cc: Matt Turner <mattst88@gmail.com>
Cc: netdev@vger.kernel.org
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: sparclinux@vger.kernel.org

Jiri Slaby (SUSE) (29):
  tty: convert "TTY Struct Flags" to an enum
  tty: audit: do not use N_TTY_BUF_SIZE
  tty: caif: do not use N_TTY_BUF_SIZE
  tty: move N_TTY_BUF_SIZE to n_tty
  tty: n_tty: use uint for space returned by tty_write_room()
  tty: n_tty: simplify process_output()
  tty: n_tty: clean up process_output_block()
  tty: n_tty: drop n_tty_trace()
  tty: n_tty: extract n_tty_continue_cookie() from n_tty_read()
  tty: n_tty: extract n_tty_wait_for_input()
  tty: n_tty: move more_to_be_read to the end of n_tty_read()
  tty: tty_driver: move TTY macros to the top
  tty: tty_driver: convert "TTY Driver Flags" to an enum
  tty: tty_driver: document both {,__}tty_alloc_driver() properly
  tty: tty_driver: introduce TTY driver sub/types enums
  tty: serdev: drop serdev_controller_ops::write_room()
  tty: moxa: drop version dump to logs
  tty: moxa: drop ISA support
  tty: moxa: carve out special ioctls and extra tty_port
  tty: srmcons: fix retval from srmcons_init()
  tty: staging/greybus: pass tty_driver flags to tty_alloc_driver()
  tty: sunsu: drop serial_{in,out}p()
  tty: sunsu: remove unused serial_icr_read()
  serial: remove redundant tty_port_link_device()
  serial: pass struct uart_state to uart_line_info()
  serial: 8250: use serial_in/out() helpers
  serial: 8250_rsa: simplify rsa8250_{request/release}_resource()
  serial: 8250_port: do not use goto for UPQ_NO_TXEN_TEST code flow
  serial: 8250_port: simplify serial8250_request_std_resource()

 Documentation/driver-api/tty/tty_driver.rst |   4 +-
 Documentation/driver-api/tty/tty_struct.rst |   2 +-
 arch/alpha/kernel/srmcons.c                 |  62 ++---
 drivers/net/caif/caif_serial.c              |   2 +-
 drivers/staging/greybus/uart.c              |   4 +-
 drivers/tty/Kconfig                         |   2 +-
 drivers/tty/moxa.c                          | 251 +-------------------
 drivers/tty/n_tty.c                         | 212 ++++++++---------
 drivers/tty/serdev/core.c                   |  11 -
 drivers/tty/serdev/serdev-ttyport.c         |   9 -
 drivers/tty/serial/8250/8250_dw.c           |  17 +-
 drivers/tty/serial/8250/8250_fsl.c          |   8 +-
 drivers/tty/serial/8250/8250_omap.c         |   2 +-
 drivers/tty/serial/8250/8250_port.c         |  59 ++---
 drivers/tty/serial/8250/8250_rsa.c          |  21 +-
 drivers/tty/serial/serial_core.c            |   6 +-
 drivers/tty/serial/sunsu.c                  | 178 ++++++--------
 drivers/tty/tty_audit.c                     |  10 +-
 drivers/tty/tty_io.c                        |   8 +-
 include/linux/serdev.h                      |   6 -
 include/linux/tty.h                         |  53 +++--
 include/linux/tty_driver.h                  | 180 +++++++-------
 22 files changed, 410 insertions(+), 697 deletions(-)

-- 
2.48.1

[PATCH 03/29] tty: caif: do not use N_TTY_BUF_SIZE

[Jiri Slaby (SUSE)]

N_TTY_BUF_SIZE -- as the name suggests -- is the N_TTY's buffer size.
There is no reason to couple that to caif's tty->receive_room. Use 4096
directly -- even though, it should be some sort of "SKB_MAX_ALLOC" or
alike. But definitely not N_TTY_BUF_SIZE.

N_TTY_BUF_SIZE is private and will be moved to n_tty.c later.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
---
 drivers/net/caif/caif_serial.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c
index ed3a589def6b..e7d1b9301fde 100644
--- a/drivers/net/caif/caif_serial.c
+++ b/drivers/net/caif/caif_serial.c
@@ -344,7 +344,7 @@ static int ldisc_open(struct tty_struct *tty)
 	ser->tty = tty_kref_get(tty);
 	ser->dev = dev;
 	debugfs_init(ser, tty);
-	tty->receive_room = N_TTY_BUF_SIZE;
+	tty->receive_room = 4096;
 	tty->disc_data = ser;
 	set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
 	rtnl_lock();
-- 
2.48.1

Re: [PATCH 03/29] tty: caif: do not use N_TTY_BUF_SIZE

[Jakub Kicinski]

On Thu, 20 Feb 2025 12:15:40 +0100 Jiri Slaby (SUSE) wrote:
> N_TTY_BUF_SIZE -- as the name suggests -- is the N_TTY's buffer size.
> There is no reason to couple that to caif's tty->receive_room. Use 4096
> directly -- even though, it should be some sort of "SKB_MAX_ALLOC" or
> alike. But definitely not N_TTY_BUF_SIZE.
> 
> N_TTY_BUF_SIZE is private and will be moved to n_tty.c later.

Acked-by: Jakub Kicinski <kuba@kernel.org>

Re: [PATCH 00/29] tty: cleanup no. 99

[Greg KH]

On Thu, Feb 20, 2025 at 12:15:37PM +0100, Jiri Slaby (SUSE) wrote:
> Hi,
> 
> this is (again) a series of cleanup in tty. I am trying to rework
> tty+serial to avoid limitations of devices (so called NR_UART or
> tty_alloc_driver()'s first parameter). And the below popped up while
> crawling through the code. So this is only a prep cleanup.
> 
> * many tty flags are now enums
> * many functions were improved for readability
> * quite a few unused or old code dropped
> 
> In particular, the runtime behaviour of the kernel before and after the
> changes is supposed to be bug to bug compatible (except moxa's ioctl
> and ISA evils dropped). That is, noone should notice.

Were you going to do a new respin of this, or do you want me to take
this as-is and you will send a follow-up ones for the commented-on
changes?

thanks,

greg k-h

Re: [PATCH 00/29] tty: cleanup no. 99

[Jiri Slaby]

On 17. 03. 25, 5:28, Greg KH wrote:
> On Thu, Feb 20, 2025 at 12:15:37PM +0100, Jiri Slaby (SUSE) wrote:
>> Hi,
>>
>> this is (again) a series of cleanup in tty. I am trying to rework
>> tty+serial to avoid limitations of devices (so called NR_UART or
>> tty_alloc_driver()'s first parameter). And the below popped up while
>> crawling through the code. So this is only a prep cleanup.
>>
>> * many tty flags are now enums
>> * many functions were improved for readability
>> * quite a few unused or old code dropped
>>
>> In particular, the runtime behaviour of the kernel before and after the
>> changes is supposed to be bug to bug compatible (except moxa's ioctl
>> and ISA evils dropped). That is, noone should notice.
> 
> Were you going to do a new respin of this, or do you want me to take
> this as-is and you will send a follow-up ones for the commented-on
> changes?

I planned to send a v2 on Fri, but did not make it. I will today.

thanks,
-- 
js
suse labs

Re: [PATCH 00/29] tty: cleanup no. 99

[Greg KH]

On Mon, Mar 17, 2025 at 05:59:01AM +0100, Jiri Slaby wrote:
> On 17. 03. 25, 5:28, Greg KH wrote:
> > On Thu, Feb 20, 2025 at 12:15:37PM +0100, Jiri Slaby (SUSE) wrote:
> > > Hi,
> > > 
> > > this is (again) a series of cleanup in tty. I am trying to rework
> > > tty+serial to avoid limitations of devices (so called NR_UART or
> > > tty_alloc_driver()'s first parameter). And the below popped up while
> > > crawling through the code. So this is only a prep cleanup.
> > > 
> > > * many tty flags are now enums
> > > * many functions were improved for readability
> > > * quite a few unused or old code dropped
> > > 
> > > In particular, the runtime behaviour of the kernel before and after the
> > > changes is supposed to be bug to bug compatible (except moxa's ioctl
> > > and ISA evils dropped). That is, noone should notice.
> > 
> > Were you going to do a new respin of this, or do you want me to take
> > this as-is and you will send a follow-up ones for the commented-on
> > changes?
> 
> I planned to send a v2 on Fri, but did not make it. I will today.

Not a problem, just wanted to make sure I didn't drop these on my side
accidentally.

thanks,

greg k-h