Add a function that returns the available link bandwidth for MST port so that we can accurately determine whether a new mode is valid for the link or not.

v2: Put the Signed-off to the end of commit message

Cc: dri-devel@lists.freedesktop.org Cc: dhinakaran.pandiyan@intel.com

Signed-off-by: Anusha Srivatsa anusha.srivatsa@intel.com --- drivers/gpu/drm/drm_dp_mst_topology.c | 12 ++++++++++++ include/drm/drm_dp_mst_helper.h | 1 + 2 files changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 04e4571..7a239f6 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -43,6 +43,8 @@ static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, char *buf); static int test_calc_pbn_mode(void);

+int drm_dp_mst_get_avail_pbn(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port); + static void drm_dp_put_port(struct drm_dp_mst_port *port);

static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, @@ -2730,6 +2732,16 @@ static int test_calc_pbn_mode(void) return 0; }

+int drm_dp_mst_get_avail_pbn(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) +{ + port = drm_dp_get_validated_port_ref(mgr,port); + if (port) + return port->available_pbn; + + return -EINVAL; +} +EXPORT_SYMBOL(drm_dp_mst_get_avail_pbn); + /* we want to kick the TX after we've ack the up/down IRQs. */ static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr) { diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h index 0032076..74dc4ab 100644 --- a/include/drm/drm_dp_mst_helper.h +++ b/include/drm/drm_dp_mst_helper.h @@ -576,6 +576,7 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_

int drm_dp_calc_pbn_mode(int clock, int bpp);

+int drm_dp_mst_get_avail_pbn(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);

bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots);