Re: [PATCH v3 10/24] drm/sun4i: tcon: Generalize engine search algorithm

Jernej Škrabec
2018-06-28T04:48:50Z

Dne četrtek, 28. junij 2018 ob 04:06:52 CEST je Chen-Yu Tsai napisal(a):
> On Mon, Jun 25, 2018 at 8:02 PM, Jernej Skrabec <jernej.skrabec-gGgVlfcn5nU@public.gmane.org>
wrote:
> > Current "old" method to find engine worked pretty well for DE2. However,
> > it doesn't work when TCON TOP is between mixer (engine) and TCON. TCON
> > TOP has multiple input ports, but current engine search algorithm
> > expects only one.
> >
> > This can be fixed by first looking for output port id and selecting
> > matching input by subtracting 1 for the next round. This work even if
> > there is only one input and output.
> >
> > Signed-off-by: Jernej Skrabec <jernej.skrabec-gGgVlfcn5nU@public.gmane.org>
> > ---
> >
> > drivers/gpu/drm/sun4i/sun4i_tcon.c | 22 ++++++++++++++++++----
> > 1 file changed, 18 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > b/drivers/gpu/drm/sun4i/sun4i_tcon.c index 08747fc3ee71..264bcc43da11
> > 100644
> > --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
> > @@ -791,12 +791,14 @@ static int sun4i_tcon_init_regmap(struct device
> > *dev,
> >
> > */
> >
> > static struct sunxi_engine *
> > sun4i_tcon_find_engine_traverse(struct sun4i_drv *drv,
> >
> > - struct device_node *node)
> > + struct device_node *node,
> > + u32 port_id)
> >
> > {
> >
> > struct device_node *port, *ep, *remote;
> > struct sunxi_engine *engine = ERR_PTR(-EINVAL);
> >
> > + u32 reg = 0;
> >
> > - port = of_graph_get_port_by_id(node, 0);
> > + port = of_graph_get_port_by_id(node, port_id);
> >
> > if (!port)
> >
> > return ERR_PTR(-EINVAL);
> >
> > @@ -826,8 +828,20 @@ sun4i_tcon_find_engine_traverse(struct sun4i_drv
> > *drv,
> >
> > if (remote == engine->node)
> >
> > goto out_put_remote;
> >
> > + /*
> > + * According to device tree binding input ports have even id
> > + * number and output ports have odd id. Since component with
> > + * more than one input and one output (TCON TOP) exits, correct
> > + * remote input id has to be calculated by subtracting 1 from
> > + * remote output id. If this for some reason can't be done, 0
> > + * is used as input port id.
> > + */
>
> You need to call
>
> of_node_put(port);
>
> to drop the reference to the original port.

Thanks for noticing it. I guess I should send fix patch, since patches from
drm-misc-next can't be dropped.

Best regards,
Jernej

> Otherwise,
>
> Reviewed-by: Chen-Yu Tsai <wens-jdAy2FN1RRM@public.gmane.org>
>
> > + port = of_graph_get_remote_port(ep);
> > + if (!of_property_read_u32(port, "reg", &reg) && reg > 0)
> > + reg -= 1;
> > +
> >
> > /* keep looking through upstream ports */
> >
> > - engine = sun4i_tcon_find_engine_traverse(drv, remote);
> > + engine = sun4i_tcon_find_engine_traverse(drv, remote, reg);
> >
> > out_put_remote:
> > of_node_put(remote);
> >
> > @@ -950,7 +964,7 @@ static struct sunxi_engine
> > *sun4i_tcon_find_engine(struct sun4i_drv *drv,>
> > /* Fallback to old method by traversing input endpoints */
> > of_node_put(port);
> >
> > - return sun4i_tcon_find_engine_traverse(drv, node);
> > + return sun4i_tcon_find_engine_traverse(drv, node, 0);
> >
> > }
> >
> > static int sun4i_tcon_bind(struct device *dev, struct device *master,
> >
> > --
> > 2.18.0

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