dri-devel Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Daniel Vetter <daniel@ffwll.ch>
To: "Michel Dänzer" <michel@daenzer.net>
Cc: Thomas Hellstrom <thellstrom@vmware.com>,
	Ira Weiny <ira.weiny@intel.com>, Kevin Brace <kevinbrace@gmx.com>,
	David Airlie <airlied@linux.ie>,
	Daniel Vetter <daniel.vetter@ffwll.ch>,
	openchrome-devel@lists.freedesktop.org,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
	dri-devel@lists.freedesktop.org,
	Mike Marshall <hubcap@omnibond.com>,
	Sam Ravnborg <sam@ravnborg.org>,
	Emil Velikov <emil.velikov@collabora.com>
Subject: Re: [PATCH/RFT v1 0/6] drm/via: drop use of deprecated headers drmP.h and drm_os_linux.h
Date: Fri, 19 Jul 2019 11:36:20 +0200	[thread overview]
Message-ID: <20190719093619.GL15868@phenom.ffwll.local> (raw)
In-Reply-To: <e2a3b772-96e7-0fed-d269-bb103057cafe@daenzer.net>

On Fri, Jul 19, 2019 at 11:05:44AM +0200, Michel Dänzer wrote:
> On 2019-07-19 8:07 a.m., Sam Ravnborg wrote:
> > On Thu, Jul 18, 2019 at 05:37:31PM +0200, Sam Ravnborg wrote:
> >> This is some janitorial updates to the via driver
> >> that is required to get rid of deprecated headers
> >> in the drm subsystem.
> >>
> >> The first three patches are trivial, where
> >> the dependencies on drmP.h and drm_os_linux are dropped.
> >>
> >> The remaining three patches drop use of DRM_WAIT_ON().
> >> They are replaced by wait_event_interruptible_timeout().
> >> These patches could use a more critical review.
> > 
> > The differences between DRM_WAIT_ON() and
> > wait_event_interruptible_timeout() are bigger than anticipated.
> > 
> > The conversion I did for drm_vblank.c is bogus thus I expect
> > the conversion done for via is also bogus.
> 
> What exactly is the problem though? Can you share information about the
> failures you're seeing?
> 
> There was some discussion about DRM_WAIT_ON() "polling" on IRC. I assume
> that refers to it only sleeping for up to 0.01s before checking the
> condition again. In contrast, wait_event_interruptible_timeout() checks
> the condition once, then sleeps up to the full timeout before checking
> it again.
> 
> If that makes a difference for drm_wait_vblank_ioctl, it indicates that
> some other code which updates the vblank count or clears vblank->enabled
> doesn't wake up the vblank->queue.

The return values differ, latest patch from Sam passes CI:

https://patchwork.freedesktop.org/patch/318909/

I have vague memories from exactly this fun when I ripped out DRM_WAIT_ON
from i915.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

  reply	other threads:[~2019-07-19  9:36 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-18 15:37 [PATCH/RFT v1 0/6] drm/via: drop use of deprecated headers drmP.h and drm_os_linux.h Sam Ravnborg
2019-07-18 15:37 ` [PATCH v1 1/6] drm/via: drop use of DRM(READ|WRITE) macros Sam Ravnborg
2019-07-18 15:37 ` [PATCH v1 2/6] drm/via: make via_drv.h self-contained Sam Ravnborg
2019-07-18 15:37 ` [PATCH v1 3/6] drm/via: drop use of drmP.h Sam Ravnborg
2019-07-18 15:37 ` [PATCH v1 4/6] drm/via: drop DRM_WAIT_ON() in via_dmablit.c Sam Ravnborg
2019-07-18 15:37 ` [PATCH v1 5/6] drm/via: drop DRM_WAIT_ON() in via_irq Sam Ravnborg
2019-07-18 15:37 ` [PATCH v1 6/6] drm/via: drop DRM_WAIT_ON() in via_video Sam Ravnborg
2019-07-19  6:07 ` [PATCH/RFT v1 0/6] drm/via: drop use of deprecated headers drmP.h and drm_os_linux.h Sam Ravnborg
2019-07-19  9:05   ` Michel Dänzer
2019-07-19  9:36     ` Daniel Vetter [this message]
2019-07-19 11:32     ` Sam Ravnborg
2019-07-19 12:37       ` Daniel Vetter
2019-07-19 15:44         ` Michel Dänzer

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190719093619.GL15868@phenom.ffwll.local \
    --to=daniel@ffwll.ch \
    --cc=airlied@linux.ie \
    --cc=daniel.vetter@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=emil.velikov@collabora.com \
    --cc=gustavo@embeddedor.com \
    --cc=hubcap@omnibond.com \
    --cc=ira.weiny@intel.com \
    --cc=kevinbrace@gmx.com \
    --cc=michel@daenzer.net \
    --cc=openchrome-devel@lists.freedesktop.org \
    --cc=sam@ravnborg.org \
    --cc=thellstrom@vmware.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox