From: Mustapha Ghaddar <mghaddar@xxxxxxx>
[WHY & HOW]
After we allocate BW at plug, we will de-alloc
and allocate only what stream needs at
stream_enable()
[HOW]
Introduce bw allocation check at link_enable()
for DPIA links
Reviewed-by: Wenjing Liu <Wenjing.Liu@xxxxxxx>
Acked-by: Qingqing Zhuo <qingqing.zhuo@xxxxxxx>
Signed-off-by: Mustapha Ghaddar <mghaddar@xxxxxxx>
---
drivers/gpu/drm/amd/display/dc/dc_link.h | 2 ++
.../gpu/drm/amd/display/dc/link/link_dpms.c | 11 +++++--
.../dc/link/protocols/link_dp_dpia_bw.c | 33 ++++++++++++++++++-
.../dc/link/protocols/link_dp_dpia_bw.h | 14 +++++++-
4 files changed, 56 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dc_link.h b/drivers/gpu/drm/amd/display/dc/dc_link.h
index cecd807f5ed8..bfe0f6877d9e 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_link.h
+++ b/drivers/gpu/drm/amd/display/dc/dc_link.h
@@ -293,6 +293,8 @@ struct dc_link {
struct dc_panel_config panel_config;
struct phy_state phy_state;
+ // BW ALLOCATON USB4 ONLY
+ struct dc_dpia_bw_alloc dpia_bw_alloc_config;
};
diff --git a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
index 180c92a9f117..a1214e5606dd 100644
--- a/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
+++ b/drivers/gpu/drm/amd/display/dc/link/link_dpms.c
@@ -46,6 +46,7 @@
#include "protocols/link_dp_capability.h"
#include "protocols/link_dp_training.h"
#include "protocols/link_edp_panel_control.h"
+#include "protocols/link_dp_dpia_bw.h"
#include "dm_helpers.h"
#include "link_enc_cfg.h"
@@ -2044,11 +2045,17 @@ static enum dc_status enable_link_dp(struct dc_state *state,
}
}
- /* Train with fallback when enabling DPIA link. Conventional links are
+ /*
+ * If the link is DP-over-USB4 do the following:
+ * - Train with fallback when enabling DPIA link. Conventional links are
* trained with fallback during sink detection.
+ * - Allocate only what the stream needs for bw in Gbps. Inform the CM
+ * in case stream needs more or less bw from what has been allocated
+ * earlier at plug time.
*/
- if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)
+ if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA) {
do_fallback = true;
+ }
/*
* Temporary w/a to get DP2.0 link rates to work with SST.
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c
index fcb82bb855ed..9d3df69fc340 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.c
@@ -246,7 +246,7 @@ static bool get_cm_response_ready_flag(struct dc_link *link)
// ------------------------------------------------------------------
// PUBLIC FUNCTIONS
// ------------------------------------------------------------------
-bool set_dptx_usb4_bw_alloc_support(struct dc_link *link)
+bool link_dp_dpia_set_dptx_usb4_bw_alloc_support(struct dc_link *link)
{
bool ret = false;
uint8_t response = 0,
@@ -439,3 +439,34 @@ int dc_link_dp_dpia_handle_usb4_bandwidth_allocation_for_link(struct dc_link *li
out:
return ret;
}
+int link_dp_dpia_allocate_usb4_bandwidth_for_stream(struct dc_link *link, int req_bw)
+{
+ int ret = 0;
+ uint8_t timeout = 10;
+
+ if (!get_bw_alloc_proceed_flag(link))
+ goto out;
+
+ /*
+ * Sometimes stream uses same timing parameters as the already
+ * allocated max sink bw so no need to re-alloc
+ */
+ if (req_bw != link->dpia_bw_alloc_config.sink_allocated_bw) {
+ dc_link_set_usb4_req_bw_req(link, req_bw);
+ do {
+ if (!timeout > 0)
+ timeout--;
+ else
+ break;
+ udelay(10 * 1000);
+ } while (!get_cm_response_ready_flag(link));
+
+ if (!timeout)
+ ret = 0;// ERROR TIMEOUT waiting for response for allocating bw
+ else if (link->dpia_bw_alloc_config.sink_allocated_bw > 0)
+ ret = get_host_router_total_bw(link, HOST_ROUTER_BW_ALLOCATED);
+ }
+
+out:
+ return ret;
+}
diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h
index c2c3049adcd1..46d141a1366f 100644
--- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h
+++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_dpia_bw.h
@@ -42,6 +42,18 @@ enum bw_type {
*
* return: SUCCESS or FAILURE
*/
-bool set_dptx_usb4_bw_alloc_support(struct dc_link *link);
+bool link_dp_dpia_set_dptx_usb4_bw_alloc_support(struct dc_link *link);
+
+/*
+ * Allocates only what the stream needs for bw, so if:
+ * If (stream_req_bw < or > already_allocated_bw_at_HPD)
+ * => Deallocate Max Bw & then allocate only what the stream needs
+ *
+ * @link: pointer to the dc_link struct instance
+ * @req_bw: Bw requested by the stream
+ *
+ * return: allocated bw else return 0
+ */
+int link_dp_dpia_allocate_usb4_bandwidth_for_stream(struct dc_link *link, int req_bw);
#endif /* DC_INC_LINK_DP_DPIA_BW_H_ */
--
2.34.1
