FROMGIT: drm/mediatek: Fix missing configuration flags in mtk_crtc_ddp_config()

In mtk_crtc_ddp_config(), mtk_crtc will use some configuration flags to
generate instructions to cmdq_handle, such as:
  state->pending_config
  mtk_crtc->pending_planes
  plane_state->pending.config
  mtk_crtc->pending_async_planes
  plane_state->pending.async_config

These configuration flags may be set to false when a GCE IRQ comes calling
ddp_cmdq_cb(). This may result in missing prepare instructions,
especially if mtk_crtc_update_config() with the flase need_vblank (no need
to wait for vblank) cases.

Therefore, the mtk_crtc->config_updating flag is set at the beginning of
mtk_crtc_update_config() to ensure that these configuration flags won't be
changed when the mtk_crtc_ddp_config() is preparing instructions.
But somehow the ddp_cmdq_cb() didn't use the mtk_crtc->config_updating
flag to prevent those pending config flags from being cleared.

To avoid missing the configuration when generating the config instruction,
the config_updating flag should be added into ddp_cmdq_cb() and be
protected with spin_lock.

Fixes: 7f82d9c4 ("drm/mediatek: Clear pending flag when cmdq packet is done")
Signed-off-by: Jason-JH.Lin <jason-jh.lin@mediatek.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Reviewed-by: Fei Shao <fshao@chromium.org>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20240827-drm-fixup-0819-v3-1-4761005211ec@mediatek.com/
Link: https://patchwork.kernel.org/project/dri-devel/patch/20240827-drm-fixup-0819-v3-2-4761005211ec@mediatek.com/


Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
(cherry picked from commit  fe30bae5 https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git

 mediatek-drm-next)

BUG=b:346360182
TEST=emerge-rauru sys-kernel/chromeos-kernel-6_6
UPSTREAM-TASK=b:326884508

Change-Id: Ifeabf53f6b40bf9ff2d3ac9512a8a69ce43e0626
Signed-off-by: Jason-jh Lin <jason-jh.lin@mediatek.corp-partner.google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/5825844


Reviewed-by: Hsin-Yi Wang <hsinyi@chromium.org>
Commit-Queue: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Sean Paul <sean@poorly.run>
Signed-off-by: Hubert Mazur <hmazur@google.com>