Re: [PATCH v7 2/9] drm/bridge: Implement generic USB Type-C DP HPD bridge

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

> > > diff --git a/drivers/gpu/drm/bridge/Makefile b/drivers/gpu/drm/bridge/Makefile
> > > index 245e8a27e3fc..e91736829167 100644
> > > --- a/drivers/gpu/drm/bridge/Makefile
> > > +++ b/drivers/gpu/drm/bridge/Makefile
> > > @@ -1,6 +1,7 @@
> > >   # SPDX-License-Identifier: GPL-2.0
> > >   obj-$(CONFIG_DRM_AUX_BRIDGE) += aux-bridge.o
> > >   obj-$(CONFIG_DRM_AUX_HPD_BRIDGE) += aux-hpd-bridge.o
> > > +obj-$(CONFIG_DRM_AUX_TYPEC_DP_HPD_BRIDGE) += aux-hpd-typec-dp-bridge.o
> > Instead, why not just make that a part of aux-hpd-bridge
> > conditionally:
> > 
> > ifneq ($(CONFIG_TYPEC),)
> >          aux-hpd-bridge-y        += aux-hpd-typec-dp-bridge.o
> > endif
> 
> Oh, I did consider that! But I noticed that aux-hpd-bridge.c contains the
> following statement module_auxiliary_driver(drm_aux_hpd_bridge_drv), which
> already includes a module_init. In the newly added file, in order to call the
> register function, another module_init was also added. If the two files are
> each made into a module separately, would there be a problem?

You would not call module_init() from the new file. Instead you would
call drm_aux_hpd_typec_dp_bridge_init() and what ever directly from
aux-hpd-bridge.c:

diff --git a/drivers/gpu/drm/bridge/aux-bridge.h b/drivers/gpu/drm/bridge/aux-bridge.h
new file mode 100644
index 000000000000..ae689a7778fa
--- /dev/null
+++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef AUX_HPD_BRIDGE_H
+#define AUX_HPD_BRIDGE_H
+
+#if IS_ENABLED(CONFIG_TYPEC)
+int drm_aux_hpd_typec_dp_bridge_init(void);
+void drm_aux_hpd_typec_dp_bridge_exit(void);
+#else
+static inline int drm_aux_hpd_typec_dp_bridge_init(void) { return 0; }
+static inline void drm_aux_hpd_typec_dp_bridge_exit(void) { }
+#endif /* IS_ENABLED(CONFIG_TYPEC) */
+
+#endif /* AUX_HPD_BRIDGE_H */
diff --git a/drivers/gpu/drm/bridge/aux-hpd-bridge.c b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
index 2e9c702c7087..3578df1df78a 100644
--- a/drivers/gpu/drm/bridge/aux-hpd-bridge.c
+++ b/drivers/gpu/drm/bridge/aux-hpd-bridge.c
@@ -12,6 +12,8 @@
 #include <drm/drm_bridge.h>
 #include <drm/bridge/aux-bridge.h>
 
+#include "aux-hpd-bridge.h"
+
 static DEFINE_IDA(drm_aux_hpd_bridge_ida);
 
 struct drm_aux_hpd_bridge_data {
@@ -190,9 +192,16 @@ static int drm_aux_hpd_bridge_probe(struct auxiliary_device *auxdev,
 
        auxiliary_set_drvdata(auxdev, data);
 
+       drm_aux_hpd_typec_dp_bridge_init();
+
        return devm_drm_bridge_add(data->dev, &data->bridge);
 }
 
+static void drm_aux_hpd_bridge_remove(struct auxiliary_device *auxdev)
+{
+       drm_aux_hpd_typec_dp_bridge_exit();
+}
+
 static const struct auxiliary_device_id drm_aux_hpd_bridge_table[] = {
        { .name = KBUILD_MODNAME ".dp_hpd_bridge", .driver_data = DRM_MODE_CONNECTOR_DisplayPort, },
        {},
@@ -203,6 +212,7 @@ static struct auxiliary_driver drm_aux_hpd_bridge_drv = {
        .name = "aux_hpd_bridge",
        .id_table = drm_aux_hpd_bridge_table,
        .probe = drm_aux_hpd_bridge_probe,
+       .remove = drm_aux_hpd_bridge_remove,
 };
 module_auxiliary_driver(drm_aux_hpd_bridge_drv);


-- 
heikki