Hi Laurent,
On 04/12/2020 22:01, Laurent Pinchart wrote:
> The rcar-du driver skips registration of the encoder for the LVDS1
> output when LVDS is used in dual-link mode, as the LVDS0 and LVDS1 links
> are bundled and handled through the LVDS0 output. It however still
> allocates the encoder and immediately destroys it, which is pointless.
> Skip allocation of the encoder altogether in that case.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
I love it when re-ordering code simplifies all the error conditions.
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/rcar-du/rcar_du_encoder.c | 51 ++++++++++-------------
> 1 file changed, 22 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
> index e4f35a88d00f..49c0b27e2f5a 100644
> --- a/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
> +++ b/drivers/gpu/drm/rcar-du/rcar_du_encoder.c
> @@ -65,17 +65,6 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,
> struct drm_bridge *bridge;
> int ret;
>
> - renc = kzalloc(sizeof(*renc), GFP_KERNEL);
> - if (renc == NULL)
> - return -ENOMEM;
> -
> - rcdu->encoders[output] = renc;
> - renc->output = output;
> - encoder = rcar_encoder_to_drm_encoder(renc);
> -
> - dev_dbg(rcdu->dev, "initializing encoder %pOF for output %u\n",
> - enc_node, output);
> -
> /*
> * Locate the DRM bridge from the DT node. For the DPAD outputs, if the
> * DT node has a single port, assume that it describes a panel and
> @@ -86,23 +75,17 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,
> rcar_du_encoder_count_ports(enc_node) == 1) {
> struct drm_panel *panel = of_drm_find_panel(enc_node);
>
> - if (IS_ERR(panel)) {
> - ret = PTR_ERR(panel);
> - goto error;
> - }
> + if (IS_ERR(panel))
> + return PTR_ERR(panel);
>
> bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
> DRM_MODE_CONNECTOR_DPI);
> - if (IS_ERR(bridge)) {
> - ret = PTR_ERR(bridge);
> - goto error;
> - }
> + if (IS_ERR(bridge))
> + return PTR_ERR(bridge);
> } else {
> bridge = of_drm_find_bridge(enc_node);
> - if (!bridge) {
> - ret = -EPROBE_DEFER;
> - goto error;
> - }
> + if (!bridge)
> + return -EPROBE_DEFER;
>
> if (output == RCAR_DU_OUTPUT_LVDS0 ||
> output == RCAR_DU_OUTPUT_LVDS1)
> @@ -110,16 +93,26 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,
> }
>
> /*
> - * On Gen3 skip the LVDS1 output if the LVDS1 encoder is used as a
> - * companion for LVDS0 in dual-link mode.
> + * Create and initialize the encoder. On Gen3 skip the LVDS1 output if
> + * the LVDS1 encoder is used as a companion for LVDS0 in dual-link
> + * mode.
> */
> if (rcdu->info->gen >= 3 && output == RCAR_DU_OUTPUT_LVDS1) {
> - if (rcar_lvds_dual_link(bridge)) {
> - ret = -ENOLINK;
> - goto error;
> - }
> + if (rcar_lvds_dual_link(bridge))
> + return -ENOLINK;
> }
>
> + renc = kzalloc(sizeof(*renc), GFP_KERNEL);
> + if (renc == NULL)
> + return -ENOMEM;
> +
> + rcdu->encoders[output] = renc;
> + renc->output = output;
> + encoder = rcar_encoder_to_drm_encoder(renc);
> +
> + dev_dbg(rcdu->dev, "initializing encoder %pOF for output %u\n",
> + enc_node, output);
> +
> ret = drm_encoder_init(&rcdu->ddev, encoder, &rcar_du_encoder_funcs,
> DRM_MODE_ENCODER_NONE, NULL);
> if (ret < 0)
>
--
Regards
--
Kieran
