2022-11-28 20:38:50

by Maíra Canal

[permalink] [raw]
Subject: Re: [PATCH v2 12/17] drm/vc4: crtc: Introduce a lower-level crtc init helper

On 11/28/22 11:53, Maxime Ripard wrote:
> The current vc4_crtc_init() helper assumes that we will be using
> hardware planes and calls vc4_plane_init().
>
> While it's a reasonable assumption, we'll want to mock the plane and
> thus provide our own. Let's create a helper that will take the plane as
> an argument.
>
> Reviewed-by: Javier Martinez Canillas <[email protected]>
> Signed-off-by: Maxime Ripard <[email protected]>

Although the commit message explains a bit about why __vc4_crtc_init is
being created, it would be nice to add a comment in the code explaining
that __vc4_crtc_init can be used for tests as it allows mocking the
plane. This way the distinction between vc4_crtc_init and
__vc4_crtc_init will be cleaner to the reader.

Reviewed-by: Maíra Canal <[email protected]>

Best Regards,
- Maíra Canal

> ---
> drivers/gpu/drm/vc4/vc4_crtc.c | 52 +++++++++++++++++++++++++++---------------
> drivers/gpu/drm/vc4/vc4_drv.h | 6 +++++
> 2 files changed, 39 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_crtc.c b/drivers/gpu/drm/vc4/vc4_crtc.c
> index 333529ed3a0d..7a2c54efecb0 100644
> --- a/drivers/gpu/drm/vc4/vc4_crtc.c
> +++ b/drivers/gpu/drm/vc4/vc4_crtc.c
> @@ -1286,31 +1286,20 @@ static void vc4_set_crtc_possible_masks(struct drm_device *drm,
> }
> }
>
> -int vc4_crtc_init(struct drm_device *drm, struct platform_device *pdev,
> - struct vc4_crtc *vc4_crtc,
> - const struct vc4_crtc_data *data,
> - const struct drm_crtc_funcs *crtc_funcs,
> - const struct drm_crtc_helper_funcs *crtc_helper_funcs,
> - bool feeds_txp)
> +int __vc4_crtc_init(struct drm_device *drm,
> + struct platform_device *pdev,
> + struct vc4_crtc *vc4_crtc,
> + const struct vc4_crtc_data *data,
> + struct drm_plane *primary_plane,
> + const struct drm_crtc_funcs *crtc_funcs,
> + const struct drm_crtc_helper_funcs *crtc_helper_funcs,
> + bool feeds_txp)
> {
> struct vc4_dev *vc4 = to_vc4_dev(drm);
> struct drm_crtc *crtc = &vc4_crtc->base;
> - struct drm_plane *primary_plane;
> unsigned int i;
> int ret;
>
> - /* For now, we create just the primary and the legacy cursor
> - * planes. We should be able to stack more planes on easily,
> - * but to do that we would need to compute the bandwidth
> - * requirement of the plane configuration, and reject ones
> - * that will take too much.
> - */
> - primary_plane = vc4_plane_init(drm, DRM_PLANE_TYPE_PRIMARY, 0);
> - if (IS_ERR(primary_plane)) {
> - dev_err(drm->dev, "failed to construct primary plane\n");
> - return PTR_ERR(primary_plane);
> - }
> -
> vc4_crtc->data = data;
> vc4_crtc->pdev = pdev;
> vc4_crtc->feeds_txp = feeds_txp;
> @@ -1342,6 +1331,31 @@ int vc4_crtc_init(struct drm_device *drm, struct platform_device *pdev,
> return 0;
> }
>
> +int vc4_crtc_init(struct drm_device *drm, struct platform_device *pdev,
> + struct vc4_crtc *vc4_crtc,
> + const struct vc4_crtc_data *data,
> + const struct drm_crtc_funcs *crtc_funcs,
> + const struct drm_crtc_helper_funcs *crtc_helper_funcs,
> + bool feeds_txp)
> +{
> + struct drm_plane *primary_plane;
> +
> + /* For now, we create just the primary and the legacy cursor
> + * planes. We should be able to stack more planes on easily,
> + * but to do that we would need to compute the bandwidth
> + * requirement of the plane configuration, and reject ones
> + * that will take too much.
> + */
> + primary_plane = vc4_plane_init(drm, DRM_PLANE_TYPE_PRIMARY, 0);
> + if (IS_ERR(primary_plane)) {
> + dev_err(drm->dev, "failed to construct primary plane\n");
> + return PTR_ERR(primary_plane);
> + }
> +
> + return __vc4_crtc_init(drm, pdev, vc4_crtc, data, primary_plane,
> + crtc_funcs, crtc_helper_funcs, feeds_txp);
> +}
> +
> static int vc4_crtc_bind(struct device *dev, struct device *master, void *data)
> {
> struct platform_device *pdev = to_platform_device(dev);
> diff --git a/drivers/gpu/drm/vc4/vc4_drv.h b/drivers/gpu/drm/vc4/vc4_drv.h
> index 051c2e3b6d43..cd2002fff115 100644
> --- a/drivers/gpu/drm/vc4/vc4_drv.h
> +++ b/drivers/gpu/drm/vc4/vc4_drv.h
> @@ -888,6 +888,12 @@ int vc4_bo_debugfs_init(struct drm_minor *minor);
> /* vc4_crtc.c */
> extern struct platform_driver vc4_crtc_driver;
> int vc4_crtc_disable_at_boot(struct drm_crtc *crtc);
> +int __vc4_crtc_init(struct drm_device *drm, struct platform_device *pdev,
> + struct vc4_crtc *vc4_crtc, const struct vc4_crtc_data *data,
> + struct drm_plane *primary_plane,
> + const struct drm_crtc_funcs *crtc_funcs,
> + const struct drm_crtc_helper_funcs *crtc_helper_funcs,
> + bool feeds_txp);
> int vc4_crtc_init(struct drm_device *drm, struct platform_device *pdev,
> struct vc4_crtc *vc4_crtc, const struct vc4_crtc_data *data,
> const struct drm_crtc_funcs *crtc_funcs,
>