Re: [PATCH 8/9] usb: typec: altmodes/displayport: Notify drm subsys of hotplug events

Heikki Krogerus
2021-05-05T10:17:39Z

Hi Hans,

On Mon, May 03, 2021 at 05:46:46PM +0200, Hans de Goede wrote:
> Use the new drm_connector_find_by_fwnode() and
> drm_connector_oob_hotplug_event() functions to let drm/kms drivers
> know about DisplayPort over Type-C hotplug events.
>
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
> Changes in v2:
> - Add missing depends on DRM to TYPEC_DP_ALTMODE Kconfig entry
> ---
> drivers/usb/typec/altmodes/Kconfig | 1 +
> drivers/usb/typec/altmodes/displayport.c | 40 +++++++++++++++++++++++-
> 2 files changed, 40 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/typec/altmodes/Kconfig b/drivers/usb/typec/altmodes/Kconfig
> index 60d375e9c3c7..1a6b5e872b0d 100644
> --- a/drivers/usb/typec/altmodes/Kconfig
> +++ b/drivers/usb/typec/altmodes/Kconfig
> @@ -4,6 +4,7 @@ menu "USB Type-C Alternate Mode drivers"
>
> config TYPEC_DP_ALTMODE
> tristate "DisplayPort Alternate Mode driver"
> + depends on DRM
> help
> DisplayPort USB Type-C Alternate Mode allows DisplayPort
> displays and adapters to be attached to the USB Type-C
> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> index aa669b9cf70e..f00dfc5c14b6 100644
> --- a/drivers/usb/typec/altmodes/displayport.c
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -11,8 +11,10 @@
> #include <linux/delay.h>
> #include <linux/mutex.h>
> #include <linux/module.h>
> +#include <linux/property.h>
> #include <linux/usb/pd_vdo.h>
> #include <linux/usb/typec_dp.h>
> +#include <drm/drm_connector.h>
> #include "displayport.h"
>
> #define DP_HEADER(_dp, ver, cmd) (VDO((_dp)->alt->svid, 1, ver, cmd) \
> @@ -62,12 +64,30 @@ struct dp_altmode {
> struct work_struct work;
> struct typec_altmode *alt;
> const struct typec_altmode *port;
> + struct fwnode_handle *connector_fwnode;
> };
>
> +static void dp_altmode_notify_connector(struct dp_altmode *dp)
> +{
> + struct drm_connector_oob_hotplug_event_data data = { };
> + u8 pin_assign = DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
> +
> + data.connected = dp->data.status & DP_STATUS_HPD_STATE;
> + data.orientation = typec_altmode_get_orientation(dp->alt);
> +
> + if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK)
> + data.dp_lanes = 4;
> + else if (pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
> + data.dp_lanes = 2;
> +
> + drm_connector_oob_hotplug_event(dp->connector_fwnode, &data);
> +}
> +
> static int dp_altmode_notify(struct dp_altmode *dp)
> {
> unsigned long conf;
> u8 state;
> + int ret;
>
> if (dp->data.conf) {
> state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
> @@ -76,7 +96,12 @@ static int dp_altmode_notify(struct dp_altmode *dp)
> conf = TYPEC_STATE_USB;
> }
>
> - return typec_altmode_notify(dp->alt, conf, &dp->data);
> + ret = typec_altmode_notify(dp->alt, conf, &dp->data);
> + if (ret)
> + return ret;
> +
> + dp_altmode_notify_connector(dp);

That is now going to be always called after configuration, right? The
HPD is not necessarily issued at that point.

I think that should be called from dp_altmode_status_update(), and
probable only if there really is HPD IRQ or HPD State changes... I
think?

> + return 0;
> }

thanks,

--
heikki