[SRU][Groovy][PATCH 0/2] Revert tty changes to fix regression

[Kleber Sacilotto de Souza]

BugLink: https://bugs.launchpad.net/bugs/1925290

[Impact]
Testcase hangup01 from ubuntu_ltp_stable.pty is failing on Groovy 5.8.0-51.57.

Test case failed with:
 hangup01 1 TFAIL : hangup01.c:132: unexpected message 3
 tag=hangup01 stime=1618856629 dur=1 exit=exited stat=1

It was found that the regression was introduced by the following commits applied
via stable uddates:

dd78b0c483e3 tty: implement read_iter
3b830a9c34d5 tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer

These patches were applied via bug 1921960 ("Groovy update: upstream stable
patchset 2021-03-30").

[Fix]
Revert the patches mentioned above until a fix can be found.

[Test case]
Run the pty testsuite from ubuntu_ltp_stable.

[Where problems could occur]
If reverting these two patches is not enough to bring the code to the behavior
of the tty driver before 5.8.0-51.57 then remaining issues could still be
present on the tty code. Those issues should be caught by the ltp testcases
though.

Kleber Sacilotto de Souza (2):
  UBUNTU: SAUCE: Revert "tty: implement read_iter"
  UBUNTU: SAUCE: Revert "tty: convert tty_ldisc_ops 'read()' function to
    take a kernel pointer"

 drivers/bluetooth/hci_ldisc.c | 34 +++++++--------
 drivers/input/serio/serport.c |  4 +-
 drivers/net/ppp/ppp_async.c   |  3 +-
 drivers/net/ppp/ppp_synctty.c |  3 +-
 drivers/tty/n_gsm.c           |  3 +-
 drivers/tty/n_hdlc.c          | 60 ++++++++-----------------
 drivers/tty/n_null.c          |  3 +-
 drivers/tty/n_r3964.c         | 10 +++--
 drivers/tty/n_tracerouter.c   |  4 +-
 drivers/tty/n_tracesink.c     |  4 +-
 drivers/tty/n_tty.c           | 82 ++++++++++++++++++++---------------
 drivers/tty/tty_io.c          | 82 +++++------------------------------
 include/linux/tty_ldisc.h     |  3 +-
 net/nfc/nci/uart.c            |  3 +-
 14 files changed, 111 insertions(+), 187 deletions(-)

-- 
2.27.0