drm/amd/display: Split arbiter programming for DCN42

[Why]
We don't want to update the timeout threshold for stall recovery in
firmware dynamically for DCN42 as we're not using FAMS.

Firmware should own programming of this register since the recovery
can be broken if driver updates the value to 0.

[How]
Split program_arbiter for dcn42 and skip the part that updates the
timeout threshold.

Reviewed-by: Leo Chen <leo.chen@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Signed-off-by: Chuanyu Tseng <Chuanyu.Tseng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/hubbub/dcn42/dcn42_hubbub.c b/drivers/gpu/drm/amd/display/dc/hubbub/dcn42/dcn42_hubbub.c
index 9e4d526b6d523d9acffd8895434844ca09107809..8582dcab1f22520bd67581e444c8992d6f06b0a8 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/hubbub/dcn42/dcn42_hubbub.c
+++ b/drivers/gpu/drm/amd/display/dc/hubbub/dcn42/dcn42_hubbub.c
@@ -503,6 +503,38 @@ static void hubbub42_set_request_limit(struct hubbub *hubbub, int memory_channel
        REG_UPDATE(SDPIF_REQUEST_RATE_LIMIT, SDPIF_REQUEST_RATE_LIMIT, request_limit);
 }
 
+static bool dcn42_program_arbiter(struct hubbub *hubbub, struct dml2_display_arb_regs *arb_regs,
+                                 bool safe_to_lower)
+{
+       struct dcn20_hubbub *hubbub2 = TO_DCN20_HUBBUB(hubbub);
+
+       bool wm_pending = false;
+       uint32_t temp;
+
+       /* request backpressure and outstanding return threshold (unused)*/
+       //REG_UPDATE(DCHUBBUB_TIMEOUT_DETECTION_CTRL1, DCHUBBUB_TIMEOUT_REQ_STALL_THRESHOLD, arb_regs->req_stall_threshold);
+
+       /* 401 delta: do not update P-State stall threshold (handled by fw) */
+       // REG_UPDATE(DCHUBBUB_TIMEOUT_DETECTION_CTRL2, DCHUBBUB_TIMEOUT_PSTATE_STALL_THRESHOLD, arb_regs->pstate_stall_threshold);
+
+       if (safe_to_lower || arb_regs->allow_sdpif_rate_limit_when_cstate_req > hubbub2->allow_sdpif_rate_limit_when_cstate_req) {
+               hubbub2->allow_sdpif_rate_limit_when_cstate_req = arb_regs->allow_sdpif_rate_limit_when_cstate_req;
+
+               /* only update the required bits */
+               REG_GET(DCHUBBUB_CTRL_STATUS, DCHUBBUB_HW_DEBUG, &temp);
+               if (hubbub2->allow_sdpif_rate_limit_when_cstate_req) {
+                       temp |= (1 << 5);
+               } else {
+                       temp &= ~(1 << 5);
+               }
+               REG_UPDATE(DCHUBBUB_CTRL_STATUS, DCHUBBUB_HW_DEBUG, temp);
+       } else {
+               wm_pending = true;
+       }
+
+       return wm_pending;
+}
+
 static const struct hubbub_funcs hubbub42_funcs = {
        .update_dchub = hubbub2_update_dchub,
        .init_dchub_sys_ctx = hubbub31_init_dchub_sys_ctx,
@@ -526,7 +558,7 @@ static const struct hubbub_funcs hubbub42_funcs = {
        .program_det_segments = dcn401_program_det_segments,
        .program_compbuf_segments = dcn401_program_compbuf_segments,
        .wait_for_det_update = dcn401_wait_for_det_update,
-       .program_arbiter = dcn401_program_arbiter,
+       .program_arbiter = dcn42_program_arbiter,
        .hubbub_read_reg_state = hubbub3_read_reg_state
 };