Files
linux/drivers/gpu/drm
Inki Dae 0cbc330e12 drm/exynos: release unhandled page flip events at postclose.
This patch resolves a dead lock issue that could be incurred when
exynos_drm_crtc_dpms function was called.

The exynos_drm_crtc_dpms function waits for the completion of pended
page flip events. However, preclose callback - this releases all unhandled
page flip events - is called prior to the exynos_drm_crtc_dpms function call
when drm is closed. So at this time, this will make the exynos_drm_crtc_dpms
to wait infiniately for the completion of the page flip events.

This patch releases the unhandled page flip events at postclose instead
of preclose so that exynos_drm_crtc_dpms function can be waked up.

Changelog v2:
- fix a memory leak when drm is closed.
  . it has a memory leak when a requeste page flip is handled after
    drm_events_release() is called and before drm_fb_release()
    is called. At this time, a drm_pending_event will not be freed.
    So also this chage releases the drm_pending_event at postclose().
    And it calls drm_vblank_put() for pair if there is any unhandled page
    flip event.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
2013-12-02 22:49:20 +09:00
..
2013-10-09 15:55:33 +10:00
2013-10-09 15:55:33 +10:00
2013-08-19 14:11:44 +10:00
2013-11-06 12:05:21 +10:00
2013-11-15 09:32:23 +09:00
2013-11-06 13:23:20 +10:00
2013-11-28 14:35:23 +10:00
2013-11-06 13:23:20 +10:00

************************************************************
* For the very latest on DRI development, please see:      *
*     http://dri.freedesktop.org/                          *
************************************************************

The Direct Rendering Manager (drm) is a device-independent kernel-level
device driver that provides support for the XFree86 Direct Rendering
Infrastructure (DRI).

The DRM supports the Direct Rendering Infrastructure (DRI) in four major
ways:

    1. The DRM provides synchronized access to the graphics hardware via
       the use of an optimized two-tiered lock.

    2. The DRM enforces the DRI security policy for access to the graphics
       hardware by only allowing authenticated X11 clients access to
       restricted regions of memory.

    3. The DRM provides a generic DMA engine, complete with multiple
       queues and the ability to detect the need for an OpenGL context
       switch.

    4. The DRM is extensible via the use of small device-specific modules
       that rely extensively on the API exported by the DRM module.


Documentation on the DRI is available from:
    http://dri.freedesktop.org/wiki/Documentation
    http://sourceforge.net/project/showfiles.php?group_id=387
    http://dri.sourceforge.net/doc/

For specific information about kernel-level support, see:

    The Direct Rendering Manager, Kernel Support for the Direct Rendering
    Infrastructure
    http://dri.sourceforge.net/doc/drm_low_level.html

    Hardware Locking for the Direct Rendering Infrastructure
    http://dri.sourceforge.net/doc/hardware_locking_low_level.html

    A Security Analysis of the Direct Rendering Infrastructure
    http://dri.sourceforge.net/doc/security_low_level.html