On 03/26/2018 07:36 PM, Noralf Trønnes wrote:
Den 26.03.2018 15.02, skrev Oleksandr Andrushchenko:
Hi, Noralf!
On 03/17/2018 04:40 PM, Noralf Trønnes wrote:
Den 16.03.2018 09.03, skrev Daniel Vetter:
On Fri, Sep 8, 2017 at 6:33 PM, Daniel Vetterdaniel@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.
My plan was to pick this up after switching tinydrm over to vmalloc buffers, but that work is now waiting for the generic fbdev emulation to land.
I'm currently wandering around inside drm_fb_helper looking for a way out, I can feel the draft so there has to be an exit somewhere. I hope that in a week or two I'm done with the next version of the RFC using the drm_fb_helper mode setting code instead of the ioctl's.
At that point it will be a good thing to flush my "caches" of the drm_fb_helper code, since after looking at it for a long time, I really don't see the details anymore. So I'll pick up the unplug series then, at least the core patches should be trivial to review and get merged if the CI agrees.
Could you please estimate when unplug series can be on review? I am doing some unplug work in my PV DRM driver and would like to understand if it is feasible to wait for you or post patches as they are and then plumb in drm_dev_{enter|exit} later after your work is merged
Ok, so I have looked at the patches and some work I have lying around. As things stand now I see an opportunity to move some stuff from tinydrm into drm_simple_kms_helper as part of adding unplug support to tinydrm. This also depends on the generic fbdev emulation I'm working on. This all means that it won't be some trivial tweaking to the unplug patchset before resending it. It will take some time.
My suggestion is that you just add the core unplug patch as part of your driver submission instead of waiting for me.
drm: Use srcu to protect drm_device.unplugged https://patchwork.freedesktop.org/patch/175779/
This is exactly the patch I need. Daniel, could you please review this single patch?
I believe this patch should be good to go as-is. Please CC intel-gfx@lists.freedesktop.org if you do so to have the Intel CI verify it.
I will
As for drm_fb_helper unplug support:
drm/fb-helper: Support device unplug https://patchwork.freedesktop.org/patch/175785/
I'm not as confident in this one since I'm not sure that those drm_dev_is_unplugged() checks are really necessary. The driver has to do the check anyways. But this patch isn't necessary for you to do most of your driver side unplug protection though. You can do testing without fbdev enabled and let me to care of this when I get around to it.
I you pick up the patch(es) and need to change something, you don't have to bother with retaining my authorship
I will retain
(but please cc me).
Ok
Just claim it for your own and make it work. Less work for me when I get there (eventually).
Noralf.
Thank you, Oleksandr
Thank you, Oleksandr
Noralf.
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
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