From: Daniel Vetter <daniel@ffwll.ch>
To: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <maxime.ripard@bootlin.com>,
Sean Paul <sean@poorly.run>, David Airlie <airlied@linux.ie>,
Daniel Vetter <daniel@ffwll.ch>, Eric Anholt <eric@anholt.net>,
Eben Upton <eben@raspberrypi.org>,
Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Subject: Re: [PATCH v3 1/2] drm/file: Rehabilitate the firstopen hook for non-legacy drivers
Date: Fri, 29 Mar 2019 09:35:34 +0100 [thread overview]
Message-ID: <20190329083534.GC2665@phenom.ffwll.local> (raw)
In-Reply-To: <20190328161306.22757-2-paul.kocialkowski@bootlin.com>
On Thu, Mar 28, 2019 at 05:13:05PM +0100, Paul Kocialkowski wrote:
> The firstopen DRM driver hook was initially used to perform hardware
> initialization, which is now considered legacy. Only a single user of
> firstopen remains at this point (savage).
>
> In some specific cases, non-legacy drivers may also need to implement
> these hooks. For instance on VC4, we need to allocate a 16 MiB buffer
> for the GPU. Because it's not required for fbcon, it's a waste to
> allocate it before userspace starts using the DRM device.
>
> Using firstopen and lastclose for this allocation seems like the best
> fit, so re-habilitate the hook to allow it to be called for non-legacy
> drivers.
>
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> Reviewed-by: Eric Anholt <eric@anholt.net>
> ---
> drivers/gpu/drm/drm_file.c | 3 +--
> include/drm/drm_drv.h | 3 ---
> 2 files changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
> index b1838a41ad43..c011b5cbfb6b 100644
> --- a/drivers/gpu/drm/drm_file.c
> +++ b/drivers/gpu/drm/drm_file.c
> @@ -266,8 +266,7 @@ static int drm_setup(struct drm_device * dev)
> {
> int ret;
>
> - if (dev->driver->firstopen &&
> - drm_core_check_feature(dev, DRIVER_LEGACY)) {
> + if (dev->driver->firstopen) {
If you guys insist on this (still not a fan myself) pls pull it out of
drm_setup - that's all just legacy hw setup in there. I still think
tracking this a bit more accurately (if you want to bother with this)
would be better.
-Daniel
> ret = dev->driver->firstopen(dev);
> if (ret != 0)
> return ret;
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index ca46a45a9cce..de5637494503 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -234,9 +234,6 @@ struct drm_driver {
> * kernel driver does not really own the hardware. Instead ownershipe is
> * handled with the help of userspace through an inheritedly racy dance
> * to set/unset the VT into raw mode.
> - *
> - * Legacy drivers initialize the hardware in the @firstopen callback,
> - * which isn't even called for modern drivers.
> */
> void (*lastclose) (struct drm_device *);
>
> --
> 2.21.0
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
next prev parent reply other threads:[~2019-03-29 8:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-28 16:13 [PATCH v3 0/2] drm/vc4: Binner BO management improvements Paul Kocialkowski
2019-03-28 16:13 ` [PATCH v3 1/2] drm/file: Rehabilitate the firstopen hook for non-legacy drivers Paul Kocialkowski
2019-03-29 8:35 ` Daniel Vetter [this message]
2019-03-29 8:37 ` Daniel Vetter
2019-03-29 8:38 ` Paul Kocialkowski
2019-03-28 16:13 ` [PATCH v3 2/2] drm/vc4: Allocated/liberate the binner BO at firstopen/lastclose Paul Kocialkowski
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