[PATCH v2 09/42] thunderbolt: Re-calculate estimated bandwidth when allocation mode is enabled

[Imre Deak]

From: Mika Westerberg <mika.westerberg at linux.intel.com>

When we program the initial bandwidth estimation the DPTX (graphics
driver) has not yet read the capabilities of the monitor so the values
used are the highest possible of the involved DisplayPort IN and OUT
adapters, not the actual monitor capabilites. To allow the graphics more
accurate bandwidth estimation re-calculate it once we we receive the
bandwidth allocation mode enabled notification.

Signed-off-by: Mika Westerberg <mika.westerberg at linux.intel.com>
---
 drivers/thunderbolt/tb.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c
index 9a261560d0f4c..6679af1efd02c 100644
--- a/drivers/thunderbolt/tb.c
+++ b/drivers/thunderbolt/tb.c
@@ -2413,10 +2413,19 @@ static void tb_handle_dp_bandwidth_request(struct work_struct *work)
 
 	ret = usb4_dp_port_requested_bandwidth(in);
 	if (ret < 0) {
-		if (ret == -ENODATA)
-			tb_port_dbg(in, "no bandwidth request active\n");
-		else
+		if (ret == -ENODATA) {
+			/*
+			 * There is no request active so this means the
+			 * BW allocation mode was enabled from graphics
+			 * side. At this point we know that the graphics
+			 * driver has read the DRPX capabilities so we
+			 * can offer an better bandwidth estimatation.
+			 */
+			tb_port_dbg(in, "DPTX enabled bandwidth allocation mode, updating estimated bandwidth\n");
+			tb_recalc_estimated_bandwidth(tb);
+		} else {
 			tb_port_warn(in, "failed to read requested bandwidth\n");
+		}
 		goto put_sw;
 	}
 	requested_bw = ret;
-- 
2.39.2