From ace75e18e736bffda1eaf9fd7eab596ecccb4877 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 23 Jan 2023 08:28:20 +0200 Subject: [PATCH] thunderbolt: Handle bandwidth allocation mode enablement notification When the graphics side enables bandwidth allocation mode the DP IN adapter sends notification to the connection manager about this. Currently the handler misses this and tries to allocate 0 Mb/s that then makes the graphics side to think the request failed. Fix this by properly handling the enablement notification. Fixes: 6ce3563520be ("thunderbolt: Add support for DisplayPort bandwidth allocation mode") Signed-off-by: Mika Westerberg --- drivers/thunderbolt/tb.c | 10 +++++++--- drivers/thunderbolt/usb4.c | 7 ++++--- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/thunderbolt/tb.c b/drivers/thunderbolt/tb.c index cdd1daa..bd5d119 100644 --- a/drivers/thunderbolt/tb.c +++ b/drivers/thunderbolt/tb.c @@ -1746,11 +1746,15 @@ static void tb_handle_dp_bandwidth_request(struct work_struct *work) goto unlock; } - requested_bw = usb4_dp_port_requested_bw(in); - if (requested_bw < 0) { - tb_port_dbg(in, "no bandwidth request active\n"); + ret = usb4_dp_port_requested_bw(in); + if (ret < 0) { + if (ret == -ENODATA) + tb_port_dbg(in, "no bandwidth request active\n"); + else + tb_port_warn(in, "failed to read requested bandwidth\n"); goto unlock; } + requested_bw = ret; tb_port_dbg(in, "requested bandwidth %d Mb/s\n", requested_bw); diff --git a/drivers/thunderbolt/usb4.c b/drivers/thunderbolt/usb4.c index 2a9266f..1e5e9c1 100644 --- a/drivers/thunderbolt/usb4.c +++ b/drivers/thunderbolt/usb4.c @@ -2732,7 +2732,8 @@ int usb4_dp_port_allocate_bw(struct tb_port *port, int bw) * Reads the DPCD (graphics driver) requested bandwidth and returns it * in Mb/s. Takes the programmed granularity into account. In case of * error returns negative errno. Specifically returns %-EOPNOTSUPP if - * the adapter does not support bandwidth allocation mode. + * the adapter does not support bandwidth allocation mode, and %ENODATA + * if there is no active bandwidth request from the graphics driver. */ int usb4_dp_port_requested_bw(struct tb_port *port) { @@ -2750,10 +2751,10 @@ int usb4_dp_port_requested_bw(struct tb_port *port) ret = tb_port_read(port, &val, TB_CFG_PORT, port->cap_adap + ADP_DP_CS_8, 1); if (ret) - return 0; + return ret; if (!(val & ADP_DP_CS_8_DR)) - return 0; + return -ENODATA; return (val & ADP_DP_CS_8_REQUESTED_BW_MASK) * granularity; } -- 2.7.4