[PATCH v2 00/11] drm/tinydrm: Support device unplug

[Daniel Vetter]

On Fri, Sep 8, 2017 at 6:33 PM, Daniel Vetter <daniel at ffwll.ch> wrote:
> Hi Noralf,
>
> On Fri, Sep 08, 2017 at 05:07:19PM +0200, Noralf Trønnes wrote:
>> This adds device unplug support to drm_fb_helper, drm_fb_cma_helper
>> (fbdev) and tinydrm.
>>
>> There are several changes in this version:
>>
>> I've used Daniel's idea of protecting drm_device.unplugged with srcu to
>> provide race free drm_dev_unplug().
>>
>> The fbdev helper unplug patch has become very small with Daniel's help.
>> Ref is now taken and dropped in the existing helpers, so I could drop
>> drm_fb_helper_simple_init().
>>
>> I has annoyed me that fbdev is restored in drm_driver.last_close even if
>> fbdev isn't used. I've added a patch to fix that. This means I can drop
>> calling drm_atomic_helper_shutdown() in tinydrm_unregister(), since I
>> now can easily disable the pipeline from userspace by just closing the
>> users. Disabled pipeline means balanced regulator_enable/disable.
>>
>> The 'Embed drm_device in tinydrm_device' patch has gained
>> drm_driver.release functions after a discussion with Laurent. My
>> previous version relied on obscure freeing in tinydrm_release().
>> This means that I didn't retain the ack's.
>>
>> Laurent also caught an ugly devm_kmalloc() in
>> tinydrm_display_pipe_init() that I've fixed.
>
> I'm practically packing for my 2 weeks of conference travel already, so
> only very cursory read of the initial patches for core&fb-helpers. I think
> this looks really splendid now.
>
> But I won't have time for review for the next few week, would be good if
> you could drag some others into this discussions. Iirc there's recently
> been a few different people interested in udl (even some patches I think),
> they might be able to help out with testing&review.
>
> Also, would be great if you can submit this to intel-gfx on the next
> round, so that our CI can pick it up and give it a solid beating. Touching
> critical core paths like in patch 1 is always a bit scary.

While reviewing xen-front's hotunplug handling I just realized this
never landed. Can you pls resend and nag me to review it properly? I'd
really like to get the drm_dev_unplug stuff sorted out better.

Thanks, Daniel

>
> Thanks, Daniel
>
>>
>> Noralf.
>>
>> Noralf Trønnes (11):
>>   drm: Use srcu to protect drm_device.unplugged
>>   drm/fb-helper: Support device unplug
>>   drm/fb-helper: Ensure driver module is pinned in fb_open()
>>   drm/fb-helper: Don't restore if fbdev is not in use
>>   drm/fb-cma-helper: Make struct drm_fbdev_cma public
>>   drm/fb-cma-helper: Support device unplug
>>   drm/tinydrm: Drop driver registered message
>>   drm/tinydrm: Embed drm_device in tinydrm_device
>>   drm/tinydrm: Support device unplug in core
>>   drm/tinydrm/mi0283qt: Let the display pipe handle power
>>   drm/tinydrm: Support device unplug in drivers
>>
>>  drivers/gpu/drm/drm_drv.c                   |  54 +++++++++--
>>  drivers/gpu/drm/drm_fb_cma_helper.c         |  13 +--
>>  drivers/gpu/drm/drm_fb_helper.c             | 108 ++++++++++++++++++++--
>>  drivers/gpu/drm/tinydrm/core/tinydrm-core.c | 135 +++++++++++++++++++---------
>>  drivers/gpu/drm/tinydrm/core/tinydrm-pipe.c |  28 +++---
>>  drivers/gpu/drm/tinydrm/mi0283qt.c          |  81 +++++------------
>>  drivers/gpu/drm/tinydrm/mipi-dbi.c          |  58 +++++++++---
>>  drivers/gpu/drm/tinydrm/repaper.c           |  62 ++++++++-----
>>  drivers/gpu/drm/tinydrm/st7586.c            |  54 ++++++-----
>>  include/drm/drm_device.h                    |   9 +-
>>  include/drm/drm_drv.h                       |  15 +++-
>>  include/drm/drm_fb_cma_helper.h             |  11 ++-
>>  include/drm/drm_fb_helper.h                 |  28 ++++++
>>  include/drm/tinydrm/mipi-dbi.h              |   1 +
>>  include/drm/tinydrm/tinydrm.h               |  10 ++-
>>  15 files changed, 469 insertions(+), 198 deletions(-)
>>
>> --
>> 2.7.4
>>
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch