From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sam Ravnborg Subject: Re: [PATCH v2 1/4] drm/simple-kms: Add drm_simple_encoder_{init, create}() Date: Thu, 20 Feb 2020 19:42:30 +0100 Message-ID: <20200220184230.GA18993@ravnborg.org> References: <20200218084815.2137-1-tzimmermann@suse.de> <20200218084815.2137-2-tzimmermann@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline In-Reply-To: <20200218084815.2137-2-tzimmermann@suse.de> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" To: Thomas Zimmermann Cc: airlied@linux.ie, dri-devel@lists.freedesktop.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, virtualization@lists.linux-foundation.org, noralf@tronnes.org, daniel@ffwll.ch, alexander.deucher@amd.com, spice-devel@lists.freedesktop.org, emil.velikov@collabora.com List-Id: virtualization@lists.linuxfoundation.org Hi Thomas. On Tue, Feb 18, 2020 at 09:48:12AM +0100, Thomas Zimmermann wrote: > This patch makes the internal encoder implementation of the simple > KMS helpers available to drivers. > = > These simple-encoder helpers initialize an encoder with an empty > implementation. This covers the requirements of most of the existing > DRM drivers. A call to drm_simple_encoder_create() allocates and > initializes an encoder instance, a call to drm_simple_encoder_init() > initializes a pre-allocated instance. > = > v2: > * move simple encoder to KMS helpers > * remove name argument; simplifies implementation > * don't allocate with devm_ interfaces; unsafe with DRM > = > Signed-off-by: Thomas Zimmermann > --- > drivers/gpu/drm/drm_simple_kms_helper.c | 83 ++++++++++++++++++++++++- > include/drm/drm_simple_kms_helper.h | 7 +++ > 2 files changed, 87 insertions(+), 3 deletions(-) > = > diff --git a/drivers/gpu/drm/drm_simple_kms_helper.c b/drivers/gpu/drm/dr= m_simple_kms_helper.c > index 15fb516ae2d8..745c2f34c42b 100644 > --- a/drivers/gpu/drm/drm_simple_kms_helper.c > +++ b/drivers/gpu/drm/drm_simple_kms_helper.c > @@ -26,12 +26,90 @@ > * entity. Some flexibility for code reuse is provided through a separat= ely > * allocated &drm_connector object and supporting optional &drm_bridge > * encoder drivers. > + * > + * Many drivers use an encoder with an empty implementation. Such encode= rs > + * fulfill the minimum requirements of the display pipeline, but don't a= dd > + * additional functionality. The simple-encoder functions > + * drm_simple_encoder_init() and drm_simple_encoder_create() provide an > + * appropriate implementation. This paragraph reads a bit strange to me - I read this as a justification for addding a generic encoded that can be used by exisitg drivers. How about something like this: Many drivers requires a very simple encoder that only fullfill the minimum requirements of the display pipeline and do not add any extra functionslity. The simple-encoder functions drm_simple_encoder_init() and drm_simple_encoder_create() provides an imp=E5lmentation of such a simple encoder. The simple encoder includes automatically release of resources. And then leave it to the changelog to tell what should be done in existing drivers. > */ > = > -static const struct drm_encoder_funcs drm_simple_kms_encoder_funcs =3D { > +static const struct drm_encoder_funcs drm_simple_encoder_funcs_cleanup = =3D { > .destroy =3D drm_encoder_cleanup, > }; > = > +/** > + * drm_simple_encoder_init - Initialize a preallocated encoder > + * @dev: drm device > + * @funcs: callbacks for this encoder > + * @encoder_type: user visible type of the encoder > + * > + * Initialises a preallocated encoder that has no further functionality.= The > + * encoder will be released automatically. Settings for possible CRTC and > + * clones are left to their initial values. The encoder will be cleaned = up > + * automatically as part of the mode-setting cleanup. > + * > + * Also see drm_simple_encoder_create(). s/Also see/See also/?? > + * > + * Returns: > + * Zero on success, error code on failure. > + */ > +int drm_simple_encoder_init(struct drm_device *dev, > + struct drm_encoder *encoder, > + int encoder_type) > +{ > + return drm_encoder_init(dev, encoder, > + &drm_simple_encoder_funcs_cleanup, > + encoder_type, NULL); > +} > +EXPORT_SYMBOL(drm_simple_encoder_init); > + > +static void drm_encoder_destroy(struct drm_encoder *encoder) > +{ > + drm_encoder_cleanup(encoder); > + kfree(encoder); > +} > + > +static const struct drm_encoder_funcs drm_simple_encoder_funcs_destroy = =3D { > + .destroy =3D drm_encoder_destroy, > +}; > + > +/** > + * drm_simple_encoder_create - Allocate and initialize an encoder > + * @dev: drm device > + * @encoder_type: user visible type of the encoder > + * > + * Allocates and initialises an encoder that has no further functionalit= y. The > + * encoder will be destroyed automatically as part of the mode-setting c= leanup. > + * > + * See drm_simple_encoder_init() for more information. > + * > + * Returns: > + * The encoder on success, a pointer-encoder error code on failure. pointer-encoded? > + */ > +struct drm_encoder *drm_simple_encoder_create(struct drm_device *dev, > + int encoder_type) > +{ > + struct drm_encoder *encoder; > + int ret; > + > + encoder =3D kzalloc(sizeof(*encoder), GFP_KERNEL); > + if (!encoder) > + return ERR_PTR(-ENOMEM); > + ret =3D drm_encoder_init(dev, encoder, > + &drm_simple_encoder_funcs_destroy, > + encoder_type, NULL); > + if (ret) > + goto err_kfree; > + > + return encoder; > + > +err_kfree: > + kfree(encoder); > + return ERR_PTR(ret); > +} > +EXPORT_SYMBOL(drm_simple_encoder_create); > + > static enum drm_mode_status > drm_simple_kms_crtc_mode_valid(struct drm_crtc *crtc, > const struct drm_display_mode *mode) > @@ -288,8 +366,7 @@ int drm_simple_display_pipe_init(struct drm_device *d= ev, > return ret; > = > encoder->possible_crtcs =3D drm_crtc_mask(crtc); > - ret =3D drm_encoder_init(dev, encoder, &drm_simple_kms_encoder_funcs, > - DRM_MODE_ENCODER_NONE, NULL); > + ret =3D drm_simple_encoder_init(dev, encoder, DRM_MODE_ENCODER_NONE); > if (ret || !connector) > return ret; > = > diff --git a/include/drm/drm_simple_kms_helper.h b/include/drm/drm_simple= _kms_helper.h > index e253ba7bea9d..54d5066d90c7 100644 > --- a/include/drm/drm_simple_kms_helper.h > +++ b/include/drm/drm_simple_kms_helper.h > @@ -181,4 +181,11 @@ int drm_simple_display_pipe_init(struct drm_device *= dev, > const uint64_t *format_modifiers, > struct drm_connector *connector); > = > +int drm_simple_encoder_init(struct drm_device *dev, > + struct drm_encoder *encoder, > + int encoder_type); > + > +struct drm_encoder *drm_simple_encoder_create(struct drm_device *dev, > + int encoder_type); > + > #endif /* __LINUX_DRM_SIMPLE_KMS_HELPER_H */ Sam