Now that the fbdev helper interface for drivers is trimmed down,
update the kerneldoc for all the remaining exported functions.

I've tried to beat the DocBook a bit by reordering the function
references a bit into a more sensible ordering. But that didn't work
out at all. Hence just extend the in-code DOC: section a bit.

Also remove the LOCKING: sections - especially for the setup functions
they're totally bogus. But that's not a documentation problem, but
simply an artifact of the current rather hazardous locking around drm
init and even more so around fbdev setup ...

v2: Some further improvements:
- Also add documentation for drm_fb_helper_single_add_all_connectors,
  Dave Airlie didn't want me to kill this one from the fb helper
  interface.
- Update docs for drm_fb_helper_fill_var/fix - they should be used
  from the driver's ->fb_probe callback to setup the fbdev info
  structure.
- Clarify what the ->fb_probe callback should all do - it needs to
  setup both the fbdev info and allocate the drm framebuffer used as
  backing storage.
- Add basic documentaation for the drm_fb_helper_funcs driver callback
  vfunc.

v3: Implement clarifications Laurent Pinchart suggested in his review.

v4: Fix another mispelling Laurent spotted.

Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

No need to check whether we've allocated a new fb since we're not
always doing that. Also, we always need to register the fbdev and add
it to the panic notifier.
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The idea behind calling down into the driver's ->fb_probe function on each
hotplug seems to be able to reallocate the backing storage (if e.g. a screen
with higher resolution gets added). But that requires quite a bit of work in the
fb helper itself, since currently we limit new screens to the currently
allocated fb. An no kms driver supports fbdev fb resizing.

So don't bother and start to simplify the code by calling drm_fb_helper_set_par
directly from the fbdev hotplug function, since that's the only thing left in
drm_fb_helper_single_fb_probe which does not concern itself with fb allocation
and initial setup. Follow-on patches will streamline the initial setup
code.
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

While doing the modeset rework for drm/i915 I've noticed that the fb
helper is very liberal with the semantics of the ->set_config
interface:
- It doesn't bother clearing stale modes (e.g. when unplugging a
  screen).
- It unconditionally sets the fb, even if no mode will be set on a
  given crtc.
- The initial setup is a bit fun since we need to pick crtcs to decide
  the desired fb size, but also should set the modeset->fb pointer.
  Explain what's going on in the fixup code after the fb is allocated.

The crtc helper didn't really care, but the new i915 modeset
infrastructure did, so I've had to add a bunch of special-cases to
catch this.

Fix this all up and enforce the interface by converting the checks in
drm/i915/intel_display.c to BUG_ONs.

v2: Fix commit message spell fail spotted by Rob Clark.
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This should be done in the drivers for two reasons:
- it gets in the way of fastboot efforts
- it links the fb helpers with the crtc helpers instead of going
  through the real interface vfuncs, forcing i915 to fake all the
  ->disable callbacks used by the crtc helper to avoid ugly Oopsen

v2: Resolve conflicts since drivers still call
drm_fb_helper_single_add_all_connectors.
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Not called by anyone, and really, shouldn't be. Drivers are supposed
either drm_fb_helper_initial_config or drm_fb_helper_hotplug_event.
Originally this was done differently, but is now consolidated in the
helper functions and no longer done by drivers directly.
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It doesn't even show up in any header files and only used iternally.
Originally it was (ab)used to restore the fbcon on lastclose, but that
died with

commit e8e7a2b8
Author: Dave Airlie <airlied@redhat.com>
Date:   Thu Apr 21 22:18:32 2011 +0100

    drm/i915: restore only the mode of this driver on lastclose (v2)
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

It's only used internally for the sysrq and panic handlers provided by
the drm fb helper implementation. Hence just inline it, kill the
export and remove the confusing kerneldoc. Driver's are supposed to
call drm_fb_helper_restore_fbdev_mode on lastclose.

Note that locking is totally fubar - the sysrq case doesn't take any
locks at all. The panic handler probably shouldn't take any locks
since it'll only make things worse. Otoh it's probably better to
switch things over to the atomic modeset callbacks (and disable the
panic handler for those drivers which don't implement it).

But that's both better done in separate patches.
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

... it's required. Fix up exynos and the cma helper, and add a
corresponding WARN_ON to drm_fb_helper_restore_fbdev_mode.

Note that tegra calls the fbdev cma helper restore function also from
it's driver-load callback. Which is a bit against current practice,
since usually the call is only from ->lastclose, and initial setup is
done by drm_fb_helper_initial_config.

Also add the relevant drm DocBook entry.

v2: Add promised WARN to restore_fbdev_mode.
Reviewed-by: NRob Clark <robdclark@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

We need to make sure that the fbcon is still bound when touching the
hw, since otherwise we might corrupt the modeset state of kms clients.
X mostly works around that with VT switching and setting the VT into
raw mode, which disables most fbcon events.

Raw kms test programs though don't do that dance, and in the future
we might want to aim to abolish CONFIG_VT anyway. So improve preventive
measures a bit. To do so, extract the existing logic for handling hotplug
events (which X can't block with the current set of tricks) and reuse
it for the fbdev blanking helper.

Long-term we really need to either scrap this all and only have a OOPS
console, or come up with a saner model for device ownership sharing
between fbdev/fbcon and kms userspace.
Reviewed-by: NRob Clark <rob@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This is the first step towards introducing the new modeset locking
scheme. The plan is to put helper functions into place at all the
right places step-by-step, so that the final patch to switch on the
new locking scheme doesn't need to touch every single driver.

This helper here will serve as the shotgun solutions for all places
where a more fine-grained locking isn't (yet) implemented.

v2: Fixup kerneldoc for unlock_all.
Reviewed-by: NRob Clark <rob@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

With refcounting we need to adjust framebuffer refcounts at each
callsite - much easier to do if they all call the same little helper
function.
Reviewed-by: NRob Clark <rob@ti.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Replace references to and remove the connector property fxns, which
have been superseded with the more general object property fxns:

  + drm_connector_attach_property -> drm_object_attach_property
  + drm_connector_property_set_value -> drm_object_property_set_value
  + drm_connector_property_get_value -> drm_object_property_get_value
Signed-off-by: NRob Clark <rob@ti.com>

Again only minimal changes to make kerneldoc no longer shout. Plus a
little introduction in the form of a inline DOC: section to quickly
explain what this is all about.

v2: Fixup spelling fail.
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

kcalloc returns NULL on failure. Hence check for the return value
and exit on error to avoid NULL pointer dereference.

Fixes the following smatch errors:
drivers/gpu/drm/drm_fb_helper.c:1271 drm_setup_crtcs() error:
potential null dereference 'modes'.  (kcalloc returns null)
drivers/gpu/drm/drm_fb_helper.c:1272 drm_setup_crtcs() error:
potential null dereference 'crtcs'.  (kcalloc returns null)
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Remove unnecessary braces to silence the following type of
checkpatch warnings:
WARNING: braces {} are not necessary for single statement blocks
WARNING: braces {} are not necessary for any arm of this statement
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Converted printks to pr_* and dev_* to silence checkpatch warnings.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Fixes the following checkpatch errors:
ERROR: trailing statements should be on next line
98: FILE: gpu/drm/drm_fb_helper.c:98:
	case DRM_FORCE_OFF: s = "OFF"; break;
ERROR: trailing statements should be on next line
99: FILE: gpu/drm/drm_fb_helper.c:99:
	case DRM_FORCE_ON_DIGITAL: s = "ON - dig"; break;
ERROR: trailing statements should be on next line
101: FILE: gpu/drm/drm_fb_helper.c:101:
	case DRM_FORCE_ON: s = "ON"; break;
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Convert #include "..." to #include <path/...> in drivers/gpu/.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NDave Airlie <airlied@redhat.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: NDave Jones <davej@redhat.com>

Yet again a case where the fb helper is too intimate with the crtc
helper and calls a crtc helepr function directly instead of going
through the interface vtable.

This fixes console blanking in drm/i915 with the new i915-specific
modeset code.
Reported-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Tested-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Fixes the following sparse warning:
drivers/gpu/drm/drm_fb_helper.c:239:6: warning:
symbol 'drm_fb_helper_force_kernel_mode' was not declared. Should it be static?
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Yet again the too close relationship between the fb helper and the
crtc helper code strikes. This time around the fb helper resets all
encoder->crtc pointers to NULL before starting to set up it's own
mode. Which is total bullocks, because this will clobber the existing
output routing, which the new drm/i915 code depends upon to be
absolutely correct.

The crtc helper itself doesn't really care about that, since it
disables unused encoders in a rather roundabout way anyway.

Two places call drm_setup_crts:

- For the initial fb config. I've auditted all current drivers, and
  they all allocate their encoders with kzalloc. So there's no need to
  clear encoder->crtc once more.

- When processing hotplug events while showing the fb console. This
  one is a bit more tricky, but both the crtc helper code and the new
  drm/i915 modeset code disable encoders if their crtc is changed and
  that encoder isn't part of the new config. Also, both disable any
  disconnected outputs, too.

  Which only leaves encoders that are on, connected, but for some odd
  reason the fb helper code doesn't want to use. That would be a bug
  in the fb configuration selector, since it tries to light up as many
  outputs as possible.

v2: Kill the now unused encoders variable.
Acked-by: NDave Airlie <airlied@gmail.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Go through the interface vtable instead, because not everyone might be
using the crtc helper code.

Cc: dri-devel@lists.freedesktop.org
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Ok, this requires quite a dance to actually hit:
1) We plug in a 2nd screen, enable it in both X and (by vt-switching)
in the fbcon.
2) We disable that screen again in with xrandr.
3) We vt-switch again, so that fbcon displays on the 2nd screen, but X
on the first screen. This obviously needs a driver that doesn't switch
off unused functions when regaining the VT.
3) When X controls the vt, we unplug that screen.

Now drm_fb_helper_hotplug_event we noticed that that some crtcs are
bound, but because we still have the fbcon on the 2nd screeen we also
have bound set. Which means the fbcon wrongly assumes it's in control
of everything an happily disables the output on the 2nd screen, but
enables its fb on the first screen.

Work around this issue by counting how many crtcs are bound and how
many are bound to fbcon and assuming that when fbcon isn't bound to
all of them, it better not touch the output configuration.

Conceptually this is the same as only restoring the fbcon output
configuration on the driver's ->lastclose, when we're sure that no one
else is using kms. So this should be consistent with existing kms
drivers.

Chris has created a separate patch for the intel ddx, but I think we
should fix this issue here regardless - the fbcon messing with the
output config while it's not fully in control simply isn't a too
polite behaviour.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50772Tested-by: NMaxim A. Nikulin <M.A.Nikulin@gmail.com>
Signed-Off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Drivers for hardware without gamma support should not be forced to
implement a no-op gamma set operation.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Rob Clark <rob.clark@linaro.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

It won't find any, yet.  Fix up callers to match: standard mode codes
will look prefer r-b modes for a given size if present, EST3 mode codes
will look for exactly the r-b-ness mentioned in the mode code.  This
might mean fewer modes matched for EST3 mode codes between now and when
the DMT mode list regrows the r-b modes, but practically speaking EST3
codes don't exist in the wild.
Signed-off-by: NAdam Jackson <ajax@redhat.com>
Tested-by: NTakashi Iwai <tiwai@suse.de>
Reviewed-by: NRodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

mplayer -vo fbdev tries to create a screen that is twice as tall as the
allocated framebuffer for "doublebuffering". By default, and all in-tree
users, only sufficient memory is allocated and mapped to satisfy the
smallest framebuffer and the virtual size is no larger than the actual.
For these users, we should therefore reject any userspace request to
create a screen that requires a buffer larger than the framebuffer
originally allocated.

References: https://bugs.freedesktop.org/show_bug.cgi?id=38138Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

crtc_id is set but never used, so remove it from struct
drm_fb_helper_crtc.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

conn_limit is set but never used. Remove it from struct
drm_fb_helper.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drm_fb_helper_on|off currently manually searches for encoders
to turn on/off. Make this simpler by using the helper function.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

drm_setup_crtcs allocated modes using drm_mode_duplicate. Free
them in drm_fb_helper_crtc_free.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Add a check for panic_timeout in the drm_fb_helper_panic() notifier: if
we're going to reboot immediately, the user will not be able to see the
messages anyway, and messing with the video mode may display artifacts,
and certainly get into several layers of complexity (including mutexes and
memory allocations) which we shall be much safer to avoid.
Signed-off-by: NHugh Dickins <hughd@google.com>
[ Edited commit message and modified to short-circuit panic_timeout < 0
  instead of testing panic_timeout >= 0.  -Mandeep ]
Signed-off-by: NMandeep Singh Baines <msb@chromium.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NStéphane Marchesin <marcheu@chromium.org>
Signed-off-by: NDave Airlie <airlied@redhat.com>

So that we don't get build failures once the implicit module.h
presence is removed.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Remove the duplicate "return" statement in drm_fb_helper_panic().
Signed-off-by: NLin Ming <ming.m.lin@intel.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

We need to hold the dev->mode_config.mutex whilst detecting the output
status. But we also need to drop it for the call into
drm_fb_helper_single_fb_probe(), which indirectly acquires the lock when
attaching the fbcon.

Failure to do so exposes a race with normal output probing. Detected by
adding some warnings that the mutex is held to the backend detect routines:

[   17.772456] WARNING: at drivers/gpu/drm/i915/intel_crt.c:471 intel_crt_detect+0x3e/0x373 [i915]()
[   17.772458] Hardware name: Latitude E6400
[   17.772460] Modules linked in: ....
[   17.772582] Pid: 11, comm: kworker/0:1 Tainted: G        W 2.6.38.4-custom.2 #8
[   17.772584] Call Trace:
[   17.772591]  [<ffffffff81046af5>] ? warn_slowpath_common+0x78/0x8c
[   17.772603]  [<ffffffffa03f3e5c>] ? intel_crt_detect+0x3e/0x373 [i915]
[   17.772612]  [<ffffffffa0355d49>] ?  drm_helper_probe_single_connector_modes+0xbf/0x2af [drm_kms_helper]
[   17.772619]  [<ffffffffa03534d5>] ?  drm_fb_helper_probe_connector_modes+0x39/0x4d [drm_kms_helper]
[   17.772625]  [<ffffffffa0354760>] ?  drm_fb_helper_hotplug_event+0xa5/0xc3 [drm_kms_helper]
[   17.772633]  [<ffffffffa035577f>] ? output_poll_execute+0x146/0x17c [drm_kms_helper]
[   17.772638]  [<ffffffff81193c01>] ? cfq_init_queue+0x247/0x345
[   17.772644]  [<ffffffffa0355639>] ? output_poll_execute+0x0/0x17c [drm_kms_helper]
[   17.772648]  [<ffffffff8105b540>] ? process_one_work+0x193/0x28e
[   17.772652]  [<ffffffff8105c6bc>] ? worker_thread+0xef/0x172
[   17.772655]  [<ffffffff8105c5cd>] ? worker_thread+0x0/0x172
[   17.772658]  [<ffffffff8105c5cd>] ? worker_thread+0x0/0x172
[   17.772663]  [<ffffffff8105f767>] ? kthread+0x7a/0x82
[   17.772668]  [<ffffffff8100a724>] ? kernel_thread_helper+0x4/0x10
[   17.772671]  [<ffffffff8105f6ed>] ? kthread+0x0/0x82
[   17.772674]  [<ffffffff8100a720>] ? kernel_thread_helper+0x0/0x10
Reported-by: NFrederik Himpe <fhimpe@telenet.be>
References: https://bugs.freedesktop.org/show_bug.cgi?id=36394Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDave Airlie <airlied@redhat.com>

In the absence of configuration data for providing the fixed mode for
a panel, I would like to be able to pass such modes along a separate
module paramenter. To do so, I then need to parse a modeline from a
string, which drm is already capable of. Export that capability to the
drivers.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDave Airlie <airlied@redhat.com>

We need to hold the dev->mode_config.mutex whilst detecting the output
status. But we also need to drop it for the call into
drm_fb_helper_single_fb_probe(), which indirectly acquires the lock when
attaching the fbcon.

Failure to do so exposes a race with normal output probing. Detected by
adding some warnings that the mutex is held to the backend detect routines:

[   17.772456] WARNING: at drivers/gpu/drm/i915/intel_crt.c:471 intel_crt_detect+0x3e/0x373 [i915]()
[   17.772458] Hardware name: Latitude E6400
[   17.772460] Modules linked in: ....
[   17.772582] Pid: 11, comm: kworker/0:1 Tainted: G        W 2.6.38.4-custom.2 #8
[   17.772584] Call Trace:
[   17.772591]  [<ffffffff81046af5>] ? warn_slowpath_common+0x78/0x8c
[   17.772603]  [<ffffffffa03f3e5c>] ? intel_crt_detect+0x3e/0x373 [i915]
[   17.772612]  [<ffffffffa0355d49>] ?  drm_helper_probe_single_connector_modes+0xbf/0x2af [drm_kms_helper]
[   17.772619]  [<ffffffffa03534d5>] ?  drm_fb_helper_probe_connector_modes+0x39/0x4d [drm_kms_helper]
[   17.772625]  [<ffffffffa0354760>] ?  drm_fb_helper_hotplug_event+0xa5/0xc3 [drm_kms_helper]
[   17.772633]  [<ffffffffa035577f>] ? output_poll_execute+0x146/0x17c [drm_kms_helper]
[   17.772638]  [<ffffffff81193c01>] ? cfq_init_queue+0x247/0x345
[   17.772644]  [<ffffffffa0355639>] ? output_poll_execute+0x0/0x17c [drm_kms_helper]
[   17.772648]  [<ffffffff8105b540>] ? process_one_work+0x193/0x28e
[   17.772652]  [<ffffffff8105c6bc>] ? worker_thread+0xef/0x172
[   17.772655]  [<ffffffff8105c5cd>] ? worker_thread+0x0/0x172
[   17.772658]  [<ffffffff8105c5cd>] ? worker_thread+0x0/0x172
[   17.772663]  [<ffffffff8105f767>] ? kthread+0x7a/0x82
[   17.772668]  [<ffffffff8100a724>] ? kernel_thread_helper+0x4/0x10
[   17.772671]  [<ffffffff8105f6ed>] ? kthread+0x0/0x82
[   17.772674]  [<ffffffff8100a720>] ? kernel_thread_helper+0x0/0x10
Reported-by: NFrederik Himpe <fhimpe@telenet.be>
References: https://bugs.freedesktop.org/show_bug.cgi?id=36394Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDave Airlie <airlied@redhat.com>

i915 calls the panic handler function on last close to reset the modes,
however this is a really bad idea for multi-gpu machines, esp shareable
gpus machines. So add a new entry point for the driver to just restore
its own fbcon mode.

v2: move code into fb helper, fix panic code to block mode change on
powered off GPUs.

[airlied: this hits drm core and I wrote it and it was reviewed on intel-gfx
 so really I signed it off twice ;-).]
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Index i was already used in thhe first loop
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>