[0/4] Mediatek DRM driver detect CMDQ execution timeout by vblank IRQ

Message

Chun-Kuang Hu Sept. 27, 2020, 11:04 p.m. UTC

CMDQ helper provide timer to detect execution timeout, but DRM driver
could have a better way to detect execution timeout by vblank IRQ.
For DRM, CMDQ command should execute in vblank, so if it fail to
execute in next 2 vblank, timeout happen. Even though we could
calculate time between 2 vblank and use timer to delect, this would
make things more complicated.

This introduce a series refinement for CMDQ mailbox controller and CMDQ
helper. Remove timer handler in helper function because different
client have different way to detect timeout. Use standard mailbox
callback instead of proprietary one to get the necessary data
in callback function. Remove struct cmdq_client to access client
instance data by struct mbox_client.

Chun-Kuang Hu (4):
  soc / drm: mediatek: cmdq: Remove timeout handler in helper function
  mailbox / soc / drm: mediatek: Use mailbox rx_callback instead of
    cmdq_task_cb
  mailbox / soc / drm: mediatek: Remove struct cmdq_client
  drm/mediatek: Detect CMDQ execution timeout

 drivers/gpu/drm/mediatek/mtk_drm_crtc.c  |  54 ++++++---
 drivers/mailbox/mtk-cmdq-mailbox.c       |  24 ++--
 drivers/soc/mediatek/mtk-cmdq-helper.c   | 146 ++---------------------
 include/linux/mailbox/mtk-cmdq-mailbox.h |  25 +---
 include/linux/soc/mediatek/mtk-cmdq.h    |  54 +--------
 5 files changed, 66 insertions(+), 237 deletions(-)

Comments

Jassi Brar Oct. 2, 2020, 8:29 p.m. UTC | #1

On Sun, Sep 27, 2020 at 6:04 PM Chun-Kuang Hu <[e-mail]> wrote:
>
> CMDQ helper provide timer to detect execution timeout, but DRM driver
> could have a better way to detect execution timeout by vblank IRQ.
> For DRM, CMDQ command should execute in vblank, so if it fail to
> execute in next 2 vblank, timeout happen. Even though we could
> calculate time between 2 vblank and use timer to delect, this would
> make things more complicated.
>
> This introduce a series refinement for CMDQ mailbox controller and CMDQ
> helper. Remove timer handler in helper function because different
> client have different way to detect timeout. Use standard mailbox
> callback instead of proprietary one to get the necessary data
> in callback function. Remove struct cmdq_client to access client
> instance data by struct mbox_client.
>
> Chun-Kuang Hu (4):
>   soc / drm: mediatek: cmdq: Remove timeout handler in helper function
>   mailbox / soc / drm: mediatek: Use mailbox rx_callback instead of
>     cmdq_task_cb
>   mailbox / soc / drm: mediatek: Remove struct cmdq_client
>   drm/mediatek: Detect CMDQ execution timeout
>
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c  |  54 ++++++---
>  drivers/mailbox/mtk-cmdq-mailbox.c       |  24 ++--
>  drivers/soc/mediatek/mtk-cmdq-helper.c   | 146 ++---------------------
>  include/linux/mailbox/mtk-cmdq-mailbox.h |  25 +---
>  include/linux/soc/mediatek/mtk-cmdq.h    |  54 +--------
>  5 files changed, 66 insertions(+), 237 deletions(-)
>
Please break this into two patchsets - one for mailbox and one for its users.
Also, CC original author and recent major contributors to mtk-cmdq-mailbox.c

Thanks.

Chun-Kuang Hu Oct. 3, 2020, 3:22 a.m. UTC | #2

Hi, Jassi:

Jassi Brar <[e-mail]> 於 2020年10月3日 週六 上午4:30寫道：
>
> On Sun, Sep 27, 2020 at 6:04 PM Chun-Kuang Hu <[e-mail]> wrote:
> >
> > CMDQ helper provide timer to detect execution timeout, but DRM driver
> > could have a better way to detect execution timeout by vblank IRQ.
> > For DRM, CMDQ command should execute in vblank, so if it fail to
> > execute in next 2 vblank, timeout happen. Even though we could
> > calculate time between 2 vblank and use timer to delect, this would
> > make things more complicated.
> >
> > This introduce a series refinement for CMDQ mailbox controller and CMDQ
> > helper. Remove timer handler in helper function because different
> > client have different way to detect timeout. Use standard mailbox
> > callback instead of proprietary one to get the necessary data
> > in callback function. Remove struct cmdq_client to access client
> > instance data by struct mbox_client.
> >
> > Chun-Kuang Hu (4):
> >   soc / drm: mediatek: cmdq: Remove timeout handler in helper function
> >   mailbox / soc / drm: mediatek: Use mailbox rx_callback instead of
> >     cmdq_task_cb
> >   mailbox / soc / drm: mediatek: Remove struct cmdq_client
> >   drm/mediatek: Detect CMDQ execution timeout
> >
> >  drivers/gpu/drm/mediatek/mtk_drm_crtc.c  |  54 ++++++---
> >  drivers/mailbox/mtk-cmdq-mailbox.c       |  24 ++--
> >  drivers/soc/mediatek/mtk-cmdq-helper.c   | 146 ++---------------------
> >  include/linux/mailbox/mtk-cmdq-mailbox.h |  25 +---
> >  include/linux/soc/mediatek/mtk-cmdq.h    |  54 +--------
> >  5 files changed, 66 insertions(+), 237 deletions(-)
> >
> Please break this into two patchsets - one for mailbox and one for its users.
> Also, CC original author and recent major contributors to mtk-cmdq-mailbox.c
>

Agree with you. But for patch [2/4] ("Use mailbox rx_callback instead
of cmdq_task_cb"), I think it would be a long term process.
I would break it into:

1. mtk-cmdq-mailbox.c: add rx_callback and keep  cmdq_task_cb because
client is using cmdq_task_cb.
2. client: change from cmdq_task_cb to rx_callback.
3. mtk-cmdq-mailbox.c: remove cmdq_task_cb.

The three step has dependency, but the 2nd should move to another
series, so I would go 1st step first.

Regards,
Chun-Kuang.

> Thanks.