@@ -85,12 +85,77 @@ static int rv1_determine_dppclk_threshol
return disp_clk_threshold;
}
-static void ramp_up_dispclk_with_dpp(struct clk_mgr_internal *clk_mgr, struct dc *dc, struct dc_clocks *new_clocks)
+static void ramp_up_dispclk_with_dpp(
+ struct clk_mgr_internal *clk_mgr,
+ struct dc *dc,
+ struct dc_clocks *new_clocks,
+ bool safe_to_lower)
{
int i;
int dispclk_to_dpp_threshold = rv1_determine_dppclk_threshold(clk_mgr, new_clocks);
bool request_dpp_div = new_clocks->dispclk_khz > new_clocks->dppclk_khz;
+ /* this function is to change dispclk, dppclk and dprefclk according to
+ * bandwidth requirement. Its call stack is rv1_update_clocks -->
+ * update_clocks --> dcn10_prepare_bandwidth / dcn10_optimize_bandwidth
+ * --> prepare_bandwidth / optimize_bandwidth. before change dcn hw,
+ * prepare_bandwidth will be called first to allow enough clock,
+ * watermark for change, after end of dcn hw change, optimize_bandwidth
+ * is executed to lower clock to save power for new dcn hw settings.
+ *
+ * below is sequence of commit_planes_for_stream:
+ *
+ * step 1: prepare_bandwidth - raise clock to have enough bandwidth
+ * step 2: lock_doublebuffer_enable
+ * step 3: pipe_control_lock(true) - make dchubp register change will
+ * not take effect right way
+ * step 4: apply_ctx_for_surface - program dchubp
+ * step 5: pipe_control_lock(false) - dchubp register change take effect
+ * step 6: optimize_bandwidth --> dc_post_update_surfaces_to_stream
+ * for full_date, optimize clock to save power
+ *
+ * at end of step 1, dcn clocks (dprefclk, dispclk, dppclk) may be
+ * changed for new dchubp configuration. but real dcn hub dchubps are
+ * still running with old configuration until end of step 5. this need
+ * clocks settings at step 1 should not less than that before step 1.
+ * this is checked by two conditions: 1. if (should_set_clock(safe_to_lower
+ * , new_clocks->dispclk_khz, clk_mgr_base->clks.dispclk_khz) ||
+ * new_clocks->dispclk_khz == clk_mgr_base->clks.dispclk_khz)
+ * 2. request_dpp_div = new_clocks->dispclk_khz > new_clocks->dppclk_khz
+ *
+ * the second condition is based on new dchubp configuration. dppclk
+ * for new dchubp may be different from dppclk before step 1.
+ * for example, before step 1, dchubps are as below:
+ * pipe 0: recout=(0,40,1920,980) viewport=(0,0,1920,979)
+ * pipe 1: recout=(0,0,1920,1080) viewport=(0,0,1920,1080)
+ * for dppclk for pipe0 need dppclk = dispclk
+ *
+ * new dchubp pipe split configuration:
+ * pipe 0: recout=(0,0,960,1080) viewport=(0,0,960,1080)
+ * pipe 1: recout=(960,0,960,1080) viewport=(960,0,960,1080)
+ * dppclk only needs dppclk = dispclk /2.
+ *
+ * dispclk, dppclk are not lock by otg master lock. they take effect
+ * after step 1. during this transition, dispclk are the same, but
+ * dppclk is changed to half of previous clock for old dchubp
+ * configuration between step 1 and step 6. This may cause p-state
+ * warning intermittently.
+ *
+ * for new_clocks->dispclk_khz == clk_mgr_base->clks.dispclk_khz, we
+ * need make sure dppclk are not changed to less between step 1 and 6.
+ * for new_clocks->dispclk_khz > clk_mgr_base->clks.dispclk_khz,
+ * new display clock is raised, but we do not know ratio of
+ * new_clocks->dispclk_khz and clk_mgr_base->clks.dispclk_khz,
+ * new_clocks->dispclk_khz /2 does not guarantee equal or higher than
+ * old dppclk. we could ignore power saving different between
+ * dppclk = displck and dppclk = dispclk / 2 between step 1 and step 6.
+ * as long as safe_to_lower = false, set dpclk = dispclk to simplify
+ * condition check.
+ * todo: review this change for other asic.
+ **/
+ if (!safe_to_lower)
+ request_dpp_div = false;
+
/* set disp clk to dpp clk threshold */
clk_mgr->funcs->set_dispclk(clk_mgr, dispclk_to_dpp_threshold);
@@ -209,7 +274,7 @@ static void rv1_update_clocks(struct clk
/* program dispclk on = as a w/a for sleep resume clock ramping issues */
if (should_set_clock(safe_to_lower, new_clocks->dispclk_khz, clk_mgr_base->clks.dispclk_khz)
|| new_clocks->dispclk_khz == clk_mgr_base->clks.dispclk_khz) {
- ramp_up_dispclk_with_dpp(clk_mgr, dc, new_clocks);
+ ramp_up_dispclk_with_dpp(clk_mgr, dc, new_clocks, safe_to_lower);
clk_mgr_base->clks.dispclk_khz = new_clocks->dispclk_khz;
send_request_to_lower = true;
}