Re: [PATCH 00/14] drm: Make DRM's IRQ helpers legacy

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Sam

Am 01.08.21 um 22:24 schrieb Sam Ravnborg:
Hi Thomas,


1) IRQ_NOTCONNECTED

We do not have this check in drm_irq today and we should avoid spreading
it all over. We are either carrying it forever or we wil lsee patches
floating in to drop the check again.
The current use in the kernel is minimal:
https://elixir.bootlin.com/linux/latest/A/ident/IRQ_NOTCONNECTED

So as a minimum drop it from atmel_hlcdc and preferably from the rest as
it is really not used. (Speaking as atmel_hlcdc maintainer)

I'll drop it from atmel_hlcdc then.

But saying that it's not used is not correct.
My point is the drm_irq do not check this - so adding this check add
something there was not needed/done before.

What is being done at [1] is actually a check for unassigned interrupts. It's just that both, test and errno code, are plain wrong. The patchset fixes this.


2) devm_request_irq()

We are moving towards managed allocation so we do not fail to free
resources. And an irq has a lifetime equal the device itself - so an
obvious cnadidate for devm_request_irq.
If we do not introduce it now we will see a revisit of this later.
I can be convinced to wait with this as we will have to do much more in
each driver, but I cannot see any good arguments to avoid the more
modern way to use devm_request_irq.

I'll change this in atmel_hdlcd and maybe I can find trivial cases where
devm_request_irq() can be used. But drivers that had an uninstall callback
before should not have the cleanup logic altered by a patch as this one. I
suspect that most of the IRQ cleanup
is actually a vblank cleanup and should be done in response to
drm_vblank_init(). But that's again not something for this patchset here. We
cannot change multiple things at once and still expect any of it to work.

I welcome the use of devm_ et al. But these changes are better done in a
per-driver patchset that changes all of the driver to managed release.
Fair enough, and fine with me.
I have yet to read through all patches - will do so in the coming week.

OK, thanks a lot. I'll send out a new revision soon, so maybe don't waste time with this one.

Best regards
Thomas


[1] https://elixir.bootlin.com/linux/latest/source/drivers/gpu/drm/drm_irq.c#L111




	Sam


--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

Attachment: OpenPGP_signature
Description: OpenPGP digital signature


[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux