From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Anholt Subject: Re: [PATCH v2 1/2] drm/file: Rehabilitate the firstopen hook for non-legacy drivers Date: Wed, 20 Mar 2019 09:56:45 -0700 Message-ID: <87zhpph4c2.fsf@anholt.net> References: <20190320154809.14823-1-paul.kocialkowski@bootlin.com> <20190320154809.14823-2-paul.kocialkowski@bootlin.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Return-path: In-Reply-To: <20190320154809.14823-2-paul.kocialkowski@bootlin.com> Sender: linux-kernel-owner@vger.kernel.org To: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Daniel Vetter , Eben Upton , Thomas Petazzoni , Paul Kocialkowski List-Id: dri-devel@lists.freedesktop.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Paul Kocialkowski writes: > 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 > --- > drivers/gpu/drm/drm_file.c | 3 +-- > include/drm/drm_drv.h | 2 +- > 2 files changed, 2 insertions(+), 3 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; >=20=20 > - if (dev->driver->firstopen && > - drm_core_check_feature(dev, DRIVER_LEGACY)) { > + if (dev->driver->firstopen) { > ret =3D dev->driver->firstopen(dev); > if (ret !=3D 0) > return ret; > diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h > index ca46a45a9cce..aa14607e54d4 100644 > --- a/include/drm/drm_drv.h > +++ b/include/drm/drm_drv.h > @@ -236,7 +236,7 @@ struct drm_driver { > * 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. > + * modern drivers can use it for other purposes only. > */ > void (*lastclose) (struct drm_device *); Our usage in vc4 is not very different from what we called "hardware initialization" in other devices. I would rather just delete this sentence entirely. The only alternative I can think of to using a firstopen/lastclose-style allocation for this would be to allocate the bin bo on the first (non-dumb?) V3D BO allocation and refcount those to free the binner. --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE/JuuFDWp9/ZkuCBXtdYpNtH8nugFAlyScM0ACgkQtdYpNtH8 nugXdBAAqeJen5dW0cJEUJfdGcNykhWS8fCDegYx5D1IHRSC20FtJuEoEJouqhN5 c93b6+WzetYIi3KNhB7Hz2xWiI0UtDREd7yT+M+5HAeFo7FW3JYquPJVeD7NS8hu IpoJpGD2RDjyLbpp8H8nbWD2qIgZKvYtK155fp3CORM+t7RfPRFFV8bavCDWdhpH CG2IGbyhK0CD6dUM4inlEXCVHxWsVr9Zdy4prmzMohY2wSky0fE3LcE3Ls7jDply fz9G/oK8jQ49lXLG1owZnH9zBeVlgJrV6ZMEv5mxICYKT7ko5Wi57mvWqUR+3iBW arZMtWG03FT0qkcW3/LuDtGDojFVjE2DnEwc9DOh64WcE0+2v7HMyKRsqbFVahUL RKJ/rCev4mnIHTBEDoFtwr4+MaQT0jIPXkPRZ3XbwBjVti4Z5jdrWCLP5upnGFCT KK7mobXfSVh8c2u1wenfAamDqTVXSaONCw/DqDD5oJbVPuq3e7JLTY6OMmAgW0Ib lLdO+tSRarHOA4UYvh1Zx1pQKp/mLL77DeGYB5Z4HLjwfymS0A/J8Na11ADqUmEw IULBhO4HWYbq5CpgAvtg07L6NSFkzQv/C6bNKhNM2uxhbgtt6YGLTPF7qVhAlqhB SRsxE22UKPDVAy6zsoZXve4ogBOSkc/Xz43urLiNRE7d+fIkRCY= =4MEm -----END PGP SIGNATURE----- --=-=-=--