linux/include
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
..
acpi ACPI updates for 5.1-rc1 2019-03-06 13:33:11 -08:00
asm-generic kbuild: force all architectures except um to include mandatory-y 2019-03-17 12:56:32 +09:00
clocksource
crypto
drm drm i915, amdgpu, qxl and etnaviv fixes 2019-03-15 13:58:35 -07:00
dt-bindings We have a fairly balanced mix of clk driver updates and clk framework 2019-03-14 08:46:17 -07:00
keys Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-03-10 17:32:04 -07:00
kvm ARM: some cleanups, direct physical timer assignment, cache sanitization 2019-03-15 15:00:28 -07:00
linux Revert "parport: daisy: use new parport device model" 2019-03-25 14:49:00 -07:00
math-emu
media media: include: fix several typos 2019-03-01 09:45:52 -05:00
memory
misc auxdisplay: charlcd: Introduce charlcd_free() helper 2019-03-17 08:48:16 +01:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-03-14 09:28:12 -07:00
pcmcia
ras
rdma
scsi scsi: kill command serial number 2019-02-27 09:19:24 -05:00
soc IOMMU Updates for Linux v5.1 2019-03-10 12:29:52 -07:00
sound sound fixes for 5.1-rc1 2019-03-15 14:05:00 -07:00
target
trace NFS client bugfixes for Linux 5.1 2019-03-16 12:28:18 -07:00
uapi Kbuild updates for v5.1 (2nd) 2019-03-17 13:25:26 -07:00
video media updates for v5.1-rc1 2019-03-09 14:45:54 -08:00
xen