[PATCH 0/8] drm/rockchip: Flip wait clean-up
seanpaul at chromium.org
Thu Sep 15 07:02:26 PDT 2016
On Wed, Sep 14, 2016 at 8:54 AM, Tomasz Figa <tfiga at chromium.org> wrote:
> The display controller found on Rockchip SoCs supported by Rockchip DRM
> driver (VOP) is a bit problematic, because it does not provide hardware
> vblank counter. Because vblank interrupt is used to feed the software
> counter, the driver had custom code to wait for flip completion to avoid
> race between atomic flush and vblank interrupt handler.
> This, however, brought a different set of issues. In fact, even with the
> custom wait code, there is stil a race between the handler and driver
> state update (of the values used to compare with registers to determine
> if flip has completed). On top of that, legacy cursor updates are not
> implemented properly and have to wait for vblank to complete, which
> is against the API specification.
> This series attempts to clean up the driver from this custom waiting code,
> eliminating related races and bringing correct handling of legacy cursor
> plane. It also gives a nice effect of more than 100 lines of code removed.
> This is a forward port of patches from 4.4 kernel used by ChromiumOS and
> tested there. Even though the code base has not changed significantly, it
> would be nice if someone with proper testing environment could give them
> a try.
> Based on for-next branch of Sean Paul's dogwood tree:
Thanks for the patches, Tomasz.
I'll queue them up in my rockchip for-next branch.
> Tomasz Figa (8):
> drm/rockchip: Clear interrupt status bits before enabling
> drm/rockchip: Get rid of some unnecessary code
> drm/rockchip: Avoid race with vblank count increment
> drm/rockchip: Unreference framebuffers from flip work
> drm/rockchip: Replace custom wait_for_vblanks with helper
> drm/rockchip: Do not enable vblank without event
> drm/rockchip: Always signal event in next vblank after cfg_done
> drm/rockchip: Kill vop_plane_state
> drivers/gpu/drm/rockchip/rockchip_drm_drv.h | 1 -
> drivers/gpu/drm/rockchip/rockchip_drm_fb.c | 64 +------
> drivers/gpu/drm/rockchip/rockchip_drm_vop.c | 247 +++++++++++-----------------
> 3 files changed, 95 insertions(+), 217 deletions(-)
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