public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Daniel Vetter <daniel@ffwll.ch>
To: Simon Ser <contact@emersion.fr>
Cc: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>,
	Brian Starkey <brian.starkey@arm.com>,
	Liviu Dudau <liviu.dudau@arm.com>,
	Daniel Vetter <daniel@ffwll.ch>,
	Haneen Mohammed <hamohammed.sa@gmail.com>,
	"dri-devel@lists.freedesktop.org"
	<dri-devel@lists.freedesktop.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH V2 4/5] drm/vkms: Use index instead of 0 in possible crtc
Date: Tue, 18 Jun 2019 13:09:20 +0200	[thread overview]
Message-ID: <20190618110920.GT12905@phenom.ffwll.local> (raw)
In-Reply-To: <innWfwO1f7V6XAA8IXBBqGMw-4_upKRtjsPG8kg19Pl9b2Hf3Bd4V20Ow7GWhfzNUmij1uVwMuHbOp3zGderuXZGhunI0y_-khuFTOStOkI=@emersion.fr>

On Tue, Jun 18, 2019 at 07:56:23AM +0000, Simon Ser wrote:
> Interestingly, even with the previous code, possible_crtcs=1 was
> exposed to userspace [1]. I think this is because of a safeguard in
> drm_crtc_init_with_planes (drm_crtc.c:284) which sets the primary and
> cursor plane's possible_crtcs to the first CRTC if zero.
> 
> If we want to warn on possible_crtcs=0, we should probably remove this
> safeguard. Checking first whether this safeguard is used by any driver
> is probably a good idea.
> 
> [1]: https://drmdb.emersion.fr/devices/f218d1242714

Yeaht it's a bit a mess, that's why I've suggested we should bite this
bullet and fix it for real. There's a bunch others such bitmasks that many
drivers seem to not set correctly.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

  reply	other threads:[~2019-06-18 11:09 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-18  2:41 [PATCH V2 0/5] drm/vkms: Introduces writeback support Rodrigo Siqueira
2019-06-18  2:42 ` [PATCH V2 1/5] drm/vkms: Move functions from vkms_crc to vkms_composer Rodrigo Siqueira
2019-06-18  9:27   ` Daniel Vetter
2019-06-18  2:43 ` [PATCH V2 2/5] drm/vkms: Rename crc_enabled to composer_enabled Rodrigo Siqueira
2019-06-18  2:45 ` [PATCH V2 3/5] drm/vkms: Rename vkms_crc_data to vkms_data Rodrigo Siqueira
2019-06-18  2:45 ` [PATCH V2 4/5] drm/vkms: Use index instead of 0 in possible crtc Rodrigo Siqueira
2019-06-18  7:56   ` Simon Ser
2019-06-18 11:09     ` Daniel Vetter [this message]
2019-06-18  9:29   ` Daniel Vetter
2019-06-18  2:45 ` [PATCH V2 5/5] drm/vkms: Add support for writeback Rodrigo Siqueira
2019-06-18  9:33   ` Daniel Vetter
2019-06-18 22:10     ` Rodrigo Siqueira

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=20190618110920.GT12905@phenom.ffwll.local \
    --to=daniel@ffwll.ch \
    --cc=brian.starkey@arm.com \
    --cc=contact@emersion.fr \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=hamohammed.sa@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=liviu.dudau@arm.com \
    --cc=rodrigosiqueiramelo@gmail.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