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Linus Torvalds a3ac7917b7 Revert "parport: daisy: use new parport device model" 
This reverts commit 1aec421120.

Steven Rostedt reports that it causes a hang at bootup and bisected it
to this commit.

The troigger is apparently a module alias for "parport_lowlevel" that
points to "parport_pc", which causes a hang with

    modprobe -q -- parport_lowlevel

blocking forever with a backtrace like this:

    wait_for_completion_killable+0x1c/0x28
    call_usermodehelper_exec+0xa7/0x108
    __request_module+0x351/0x3d8
    get_lowlevel_driver+0x28/0x41 [parport]
    __parport_register_driver+0x39/0x1f4 [parport]
    daisy_drv_init+0x31/0x4f [parport]
    parport_bus_init+0x5d/0x7b [parport]
    parport_default_proc_register+0x26/0x1000 [parport]
    do_one_initcall+0xc2/0x1e0
    do_init_module+0x50/0x1d4
    load_module+0x1c2e/0x21b3
    sys_init_module+0xef/0x117

Supid says:
 "Due to the new device model daisy driver will now try to find the
  parallel ports while trying to register its driver so that it can bind
  with them. Now, since daisy driver is loaded while parport bus is
  initialising the list of parport is still empty and it tries to load
  the lowlevel driver, which has an alias set to parport_pc, now causes
  a deadlock"

But I don't think the daisy driver should be loaded by the parport
initialization in the first place, so let's revert the whole change.

If the daisy driver can just initialize separately on its own (like a
driver should), instead of hooking into the parport init sequence
directly, this issue probably would go away.

Reported-and-bisected-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-25 14:49:00 -07:00
..
BUGS-parport
daisy.c Revert "parport: daisy: use new parport device model" 2019-03-25 14:49:00 -07:00
ieee1284_ops.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ieee1284.c parport: ieee1284: mark expected switch fall-throughs 2018-07-15 14:13:00 +02:00
Kconfig docs: Fix some broken references 2018-06-15 18:10:01 -03:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
multiface.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
parport_amiga.c
parport_atari.c
parport_ax88796.c parport: ax88796: Delete an unnecessary variable initialisation in parport_ax88796_probe() 2018-03-14 17:54:09 +01:00
parport_cs.c
parport_gsc.c parisc/parport_gsc: Use NULL to avoid sparse warning 2018-03-27 18:52:21 +02:00
parport_gsc.h
parport_ip32.c
parport_mfc3.c
parport_pc.c parport_pc: fix find_superio io compare code, should use equal test. 2019-02-11 09:39:02 +01:00
parport_serial.c parport: parport_serial: Add WCH CH382L PCIe single parallel port support 2018-07-07 17:35:10 +02:00
parport_sunbpp.c parport: sunbpp: fix error return code 2018-07-15 14:13:00 +02:00
probe.c Revert "parport: daisy: use new parport device model" 2019-03-25 14:49:00 -07:00
procfs.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
share.c Revert "parport: daisy: use new parport device model" 2019-03-25 14:49:00 -07:00
TODO-parport