On Mon, 10 Oct 2016, "Sun, Jing A" jing.a.sun@intel.com wrote:
You're missing some lists and people from distribution, added now.
See the discussion starting at [1]. I don't know if anything has happened since then. Takashi?
BR, Jani.
[1] http://lkml.kernel.org/r/s5hh9bhvj7j.wl-tiwai@suse.de
On Mon, 10 Oct 2016 10:28:31 +0200, Jani Nikula wrote:
Unfortunately, nothing seems to have happened since my last patch due to little interest. I'd be glad if the patch is revived.
(BTW, I'm traveling in these two weeks, so the further reply will be delayed.)
thanks,
Takashi
Dear Maintainers,
It's needed that DRM Driver module could be removed and reloaded after kernel booting on the projects that I have been working on, and I hope such module type change could be accepted. Looks like Iwai has similar change request as well. Would you please review it and let us know if any concerns?
Regards, Sun, Jing
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Monday, October 10, 2016 5:57 PM To: Jani Nikula Cc: Sun, Jing A; airlied@linux.ie; Vetter, Daniel; linux-kernel@vger.kernel.org; dri-devel@lists.freedesktop.org; Takashi Iwai; a.hajda@samsung.com; Thierry Reding Subject: Re: [PATCH]"drm: change DRM_MIPI_DSI module type from "bool" to "tristate".
On Mon, 10 Oct 2016 10:28:31 +0200, Jani Nikula wrote:
Unfortunately, nothing seems to have happened since my last patch due to little interest. I'd be glad if the patch is revived.
(BTW, I'm traveling in these two weeks, so the further reply will be delayed.)
thanks,
Takashi
Hi,
This patch misses dsi bus un-registration. However I have reviewed two patches of Takashi which solves the same issue more completely [1]. These patches were not accepted neither.
[1]: https://lists.freedesktop.org/archives/dri-devel/2016-August/114870.html
Regards Andrzej
On 11.10.2016 10:40, Sun, Jing A wrote:
On Tue, 11 Oct 2016, "Sun, Jing A" jing.a.sun@intel.com wrote:
Looking at the Kconfig, selecting CONFIG_DRM_MIPI_DSI is against the recommendations of Documentation/kbuild/kconfig-language.txt:
select should be used with care. select will force a symbol to a value without visiting the dependencies. By abusing select you are able to select a symbol FOO even if FOO depends on BAR that is not set. In general use select only for non-visible symbols (no prompts anywhere) and for symbols with no dependencies. That will limit the usefulness but on the other hand avoid the illegal configurations all over.
Indeed, you may end up with CONFIG_DRM_MIPI_DSI=y and CONFIG_DRM=m, which violates DRM_MIPI_DSI dependency on CONFIG_DRM. This is broken and should be fixed. The suggested patch does *not* fix this issue.
Interestingly, I am able to reload i915 and drm. Our CI has tests for i915 unload/reload, but does not check drm. In any case the config problem should not impact the reloadability of i915.
BR, Jani.
On 11.10.2016 11:33, Jani Nikula wrote:
All existing drivers which selects DRM_MIPI_DSI also depends on DRM. So the dependency is always true. I am not sure if it could not change in the future, but in such case mipi_dsi bus should be completely detached from DRM framework, I hope we have not such case yet :)
At the moment it should not be possible.
Regards Andrzej
Interestingly, I am able to reload i915 and drm. Our CI has tests for i915 unload/reload, but does not check drm. In any case the config problem should not impact the reloadability of i915. ====== Sorry that I didn't make myself clear. In order to replace the default i915 module with an updated one, the related DRM modules also need to be updated to match the updated i915, hence the restriction.
Regards, Sun, Jing
-----Original Message----- From: Andrzej Hajda [mailto:a.hajda@samsung.com] Sent: Tuesday, October 11, 2016 5:53 PM To: Jani Nikula; Sun, Jing A; Takashi Iwai Cc: airlied@linux.ie; Vetter, Daniel; linux-kernel@vger.kernel.org; dri-devel@lists.freedesktop.org; Thierry Reding; Emil Velikov Subject: Re: [PATCH]"drm: change DRM_MIPI_DSI module type from "bool" to "tristate".
On 11.10.2016 11:33, Jani Nikula wrote:
All existing drivers which selects DRM_MIPI_DSI also depends on DRM. So the dependency is always true. I am not sure if it could not change in the future, but in such case mipi_dsi bus should be completely detached from DRM framework, I hope we have not such case yet :)
At the moment it should not be possible.
Regards Andrzej
On Wed, Oct 12, 2016 at 03:08:24AM +0000, Sun, Jing A wrote:
Just to avoid tears in the future: If you plan to ship this in product, you won't ship.
And for debugging, just install a kernel with your changes for both drm and i915.
In short, your use-case isn't really valid (but we could still make the dsi code modular if people feel like). -Daniel
I think "installing a kernel with my changes for both drm and i915" takes more time and effort to complete than "only updating DRM/i915 modules without rebuilding the whole kernel". In some cases, that's beneficial.
Also reloadablility is always a good thing to have and I truly hope Hajda/Iwai's patches would be accepted and merged. No downside of it after all.
Regards, Sun, Jing
-----Original Message----- From: Daniel Vetter [mailto:daniel.vetter@ffwll.ch] On Behalf Of Daniel Vetter Sent: Wednesday, October 12, 2016 2:52 PM To: Sun, Jing A Cc: Andrzej Hajda; Jani Nikula; Takashi Iwai; Emil Velikov; linux-kernel@vger.kernel.org; dri-devel@lists.freedesktop.org; Vetter, Daniel; Thierry Reding Subject: Re: [PATCH]"drm: change DRM_MIPI_DSI module type from "bool" to "tristate".
On Wed, Oct 12, 2016 at 03:08:24AM +0000, Sun, Jing A wrote:
Just to avoid tears in the future: If you plan to ship this in product, you won't ship.
And for debugging, just install a kernel with your changes for both drm and i915.
In short, your use-case isn't really valid (but we could still make the dsi code modular if people feel like). -Daniel
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
On Wed, 12 Oct 2016, "Sun, Jing A" jing.a.sun@intel.com wrote:
It's possible to change and rebuild and update just the drm and i915, but you need to be careful to build against the same tree as the ones you are replacing. This is like using out-of-tree modules (which is something I can't recommend no matter what, but that's another discussion).
However, this is completely different from planning to update drm and i915 modules on a running production system by unloading the old ones and probing the new ones. Don't do that. It will be a disaster.
I think it's good to be able to unload and reload modules for debugging and development, but not for normal use.
BR, Jani.
On 11 October 2016 at 10:33, Jani Nikula jani.nikula@linux.intel.com wrote:
Jani, git log suggests you as the unfortunate author of the select DRM_MIPI_DSI/select DRM_PANEL hunks in i915 ;-)
From a cutesy skim through panel/ there are a handful of things to
squash - unused select/depend on, s/select/depend on/ etc. Sadly I don't have the time to address these :-\
Regards, Emil
On Wed, 12 Oct 2016, Emil Velikov emil.l.velikov@gmail.com wrote:
/o\
As much as my present self would like to scold my past self for all his mistakes, I have to remind myself that it is the mistakes that have given me invaluable experience that my past self didn't have. I can only hope my future self will have time to fix even a fraction of the mistakes.
Anyway, as Andrzej pointed out, all configs that select DRM_MIPI_DSI also depend on DRM, so this problem can't currently occur. Once dsi bus un-registration gets addressed, we can turn DRM_MIPI_DSI into a tristate config (i.e. a loadable module).
BR, Jani.
Hi Jani,
Forgive me late response.
On 12.10.2016 16:28, Jani Nikula wrote:
There is already patch adding bus unregistration [1]. It was published together with 'tristate' patch [2], both were created by Takashi few months ago.
[1]: https://lists.freedesktop.org/archives/dri-devel/2016-August/114870.html [2]: https://lists.freedesktop.org/archives/dri-devel/2016-August/114497.html
Regards Andrzej
BR, Jani.
On Thu, 20 Oct 2016, Andrzej Hajda a.hajda@samsung.com wrote:
Right. So make that "Once dis bus un-registration gets merged upstream". ;)
BR, Jani.
On Thu, Oct 20, 2016 at 04:44:49PM +0300, Jani Nikula wrote:
Someone volunteering for some review pls? -Daniel
dri-devel@lists.freedesktop.org
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Andrzej Hajda -
Daniel Vetter -
Emil Velikov -
Jani Nikula -
Sun, Jing A -
Takashi Iwai