linux-toradex.git/drivers/gpu/drm/drm_irq.c, branch v4.19

drm/doc: Polish irq helper documentation

2017-06-01T06:02:14+00:00

Pull a (much shorter) overview into drm_irq.c, and instead put the
callback documentation into in-line comments in drm_drv.h.

v2: Move the include stanzas back to the split-up patch (Stefan).

Cc: Stefan Agner 
Reviewed-by: Stefan Agner 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170531092253.12833-1-daniel.vetter@ffwll.ch

drm: Extract drm_vblank.[hc]

2017-06-01T06:02:14+00:00

drm_irq.c contains both the irq helper library (optional) and the
vblank support (optional, but part of the modeset uapi, and doesn't
require the use of the irq helpers at all.

Split this up for more clarity of the scope of the individual bits.

v2: Move misplaced hunks to this patch (Stefan).

Cc: Stefan Agner 
Reviewed-by: Stefan Agner 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170531092146.12528-1-daniel.vetter@ffwll.ch

drm/vblank: Lock down vblank->hwmode more

2017-05-10T08:21:37+00:00

In the previous patch we've implemented hwmode tracking a la i915 for
the vblank timestamp calculations. But that was just the basic
semantics, i915 has some nice sanity checks to make sure we keep
getting this right. Move them over too.

v2:
- WARN_ON_ONCE to avoid excessive spam (Ville)
- Really only WARN on atomic drivers.

Cc: Ville Syrjälä 
Reviewed-by: Neil Armstrong 
Acked-by: Ville Syrjälä 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170509140329.24114-5-daniel.vetter@ffwll.ch

drm/vblank: drop the mode argument from drm_calc_vbltimestamp_from_scanoutpos

2017-05-10T08:21:31+00:00

If we restrict this helper to only kms drivers (which is the case) we
can look up the correct mode easily ourselves. But it's a bit tricky:

- All legacy drivers look at crtc->hwmode. But that is updated already
  at the beginning of the modeset helper, which means when we disable
  a pipe. Hence the final timestamps might be a bit off. But since
  this is an existing bug I'm not going to change it, but just try to
  be bug-for-bug compatible with the current code. This only applies
  to radeon&amdgpu.

- i915 tries to get it perfect by updating crtc->hwmode when the pipe
  is off (i.e. vblank->enabled = false).

- All other atomic drivers look at crtc->state->adjusted_mode. Those
  that look at state->requested_mode simply don't adjust their mode,
  so it's the same. That has two problems: Accessing crtc->state from
  interrupt handling code is unsafe, and it's updated before we shut
  down the pipe. For nonblocking modesets it's even worse.

For atomic drivers try to implement what i915 does. To do that we add
a new hwmode field to the vblank structure, and update it from
drm_calc_timestamping_constants(). For atomic drivers that's called
from the right spot by the helper library already, so all fine. But
for safety let's enforce that.

For legacy driver this function is only called at the end (oh the
fun), which is broken, so again let's not bother and just stay
bug-for-bug compatible.

The  benefit is that we can use drm_calc_vbltimestamp_from_scanoutpos
directly to implement ->get_vblank_timestamp in every driver, deleting
a lot of code.

v2: Completely new approach, trying to mimick the i915 solution.

v3: Fixup kerneldoc.

v4: Drop the WARN_ON to check that the vblank is off, atomic helpers
currently unconditionally call this. Recomputing the same stuff should
be harmless.

v5: Fix typos and move misplaced hunks to the right patches (Neil).

v6: Undo hunk movement (kbuild).

Cc: Mario Kleiner 
Cc: Eric Anholt 
Cc: Rob Clark 
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: Alex Deucher 
Cc: Christian König 
Cc: Ben Skeggs 
Reviewed-by: Neil Armstrong 
Acked-by: Ville Syrjälä 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170509140329.24114-4-daniel.vetter@ffwll.ch

drm/vblank: Switch to bool in_vblank_irq in get_vblank_timestamp

2017-05-10T08:21:17+00:00

It's overkill to have a flag parameter which is essentially used just
as a boolean. This takes care of core + adjusting drivers.

Adjusting the scanout position callback is a bit harder, since radeon
also supplies it's own driver-private flags in there.

v2: Fixup misplaced hunks (Neil).

v3: kbuild says v1 was better ...

Cc: Mario Kleiner 
Cc: Eric Anholt 
Cc: Rob Clark 
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: Alex Deucher 
Cc: Christian König 
Cc: Ben Skeggs 
Reviewed-by: Ville Syrjälä 
Reviewed-by: Neil Armstrong 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170509140329.24114-2-daniel.vetter@ffwll.ch

drm/vblank: Switch drm_driver->get_vblank_timestamp to return a bool

2017-05-10T08:21:08+00:00

There's really no reason for anything more:
- Calling this while the crtc vblank stuff isn't set up is a driver
  bug. Those places alrready DRM_ERROR.
- Calling this when the crtc is off is either a driver bug (calling
  drm_crtc_handle_vblank at the wrong time) or a core bug (for
  anything else). Again, we DRM_ERROR.
- EINVAL is checked at higher levels already, and if we'd use struct
  drm_crtc * instead of (dev, pipe) it would be real obvious that
  those are again core bugs.

The only valid failure mode is crap hardware that couldn't sample a
useful timestamp, to ask the core to just grab a not-so-accurate
timestamp. Bool is perfectly fine for that.

v2: Also fix up the one caller, I lost that in the shuffling (Jani).

v3: Fixup commit message (Neil).

Cc: Jani Nikula 
Cc: Mario Kleiner 
Cc: Eric Anholt 
Cc: Rob Clark 
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Cc: Alex Deucher 
Cc: Christian König 
Cc: Ben Skeggs 
Reviewed-by: Neil Armstrong 
Acked-by: Ville Syrjälä 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170509140329.24114-1-daniel.vetter@ffwll.ch

drm: Pass CRTC ID in userspace vblank events

2017-04-04T19:59:12+00:00

With the atomic API, it is possible that a single commit affects
multiple crtcs. If the user requests an event with that commit, one
event will be sent for each CRTC, but it is not possible to distinguish
which crtc an event is for in user space. To solve this, the reserved
field in struct drm_vblank_event is repurposed to include the crtc_id
which the event is for.

The DRM_CAP_CRTC_IN_VBLANK_EVENT is added to allow userspace to query if
the crtc field will be set properly.

[daniels: Rebased, using Maarten's forward-port.]

Signed-off-by: Ander Conselvan de Oliveira 
Signed-off-by: Daniel Stone 
Cc: Maarten Lankhorst 
Link: http://patchwork.freedesktop.org/patch/msgid/20170404165221.28240-2-daniels@collabora.com

drm: Convert cmpxchg(bool) back to a two step operation

2017-03-30T14:15:49+00:00

ARM v6 (at least) only allows cmpxchg on 32bit variables which doesn't
always include the bool type.

drivers/built-in.o: In function `vblank_disable_and_save':
imx-ocotp.c:(.text+0xb45e8): undefined reference to `__bad_cmpxchg'
Makefile:986: recipe for target 'vmlinux' failed

Reported-by: kbuild test robot 
Reported-by: Leonard Crestez 
Fixes: 43dc7fe2b211 ("drm: Mark up accesses of vblank->enabled outside of its spinlock")
Signed-off-by: Chris Wilson 
Cc: Ville Syrjälä 
Cc: Daniel Vetter 
Signed-off-by: Ville Syrjälä 
Link: http://patchwork.freedesktop.org/patch/msgid/20170330140832.32377-1-chris@chris-wilson.co.uk

drm: Peek at the current counter/timestamp for vblank queries

2017-03-29T11:02:22+00:00

Bypass all the spinlocks and return the last timestamp and counter from
the last vblank if the driver delcares that it is accurate (and stable
across on/off), and the vblank is currently enabled.

This is dependent upon the both the hardware and driver to provide the
proper barriers to facilitate reading our bookkeeping outside of the
vblank interrupt and outside of the explicit vblank locks.

Signed-off-by: Chris Wilson 
Cc: Ville Syrjälä 
Cc: Daniel Vetter 
Cc: Michel Dänzer 
Cc: Laurent Pinchart 
Cc: Dave Airlie ,
Cc: Mario Kleiner 
Link: http://patchwork.freedesktop.org/patch/msgid/20170317202030.24410-4-chris@chris-wilson.co.uk
Reviewed-by: Ville Syrjälä 
Signed-off-by: Ville Syrjälä

drm: Refactor vblank sequence number comparison

2017-03-29T11:00:36+00:00

Move the repeated (a - b) <= (1 << 23) to its own function.

v2: Catch the '1<<23' inside drm_handle_vblank() as well

Signed-off-by: Chris Wilson 
Cc: Ville Syrjälä 
Cc: Daniel Vetter 
Cc: Michel Dänzer 
Link: http://patchwork.freedesktop.org/patch/msgid/20170322100650.26082-1-chris@chris-wilson.co.uk
Reviewed-by: Michel Dänzer 
Reviewed-by: Ville Syrjälä 
Signed-off-by: Ville Syrjälä