[PATCH 019/120] drm/amd/display: fix decide_link_settings
Harry Wentland
harry.wentland at amd.com
Wed Aug 9 15:01:05 UTC 2017
From: Ding Wang <Ding.Wang at amd.com>
Change-Id: I564f7b593893b459d2c455ffe3c4767c030c4a96
Signed-off-by: Ding Wang <Ding.Wang at amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng at amd.com>
Acked-by: Harry Wentland <Harry.Wentland at amd.com>
---
drivers/gpu/drm/amd/display/dc/core/dc.c | 6 +-
drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 140 ++++++++++-------------
drivers/gpu/drm/amd/display/dc/dc.h | 1 +
3 files changed, 63 insertions(+), 84 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
index ad1b90563eb6..de05ad09599f 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -308,10 +308,8 @@ static void set_preferred_link_settings(struct dc *dc,
{
struct core_link *core_link = DC_LINK_TO_CORE(link);
- core_link->public.verified_link_cap.lane_count =
- link_setting->lane_count;
- core_link->public.verified_link_cap.link_rate =
- link_setting->link_rate;
+ core_link->public.preferred_link_setting =
+ *link_setting;
dp_retrain_link_dp_test(core_link, link_setting, false);
}
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index 445cd226d36d..e90b3ebc8347 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -33,32 +33,6 @@ enum {
LINK_TRAINING_MAX_CR_RETRY = 100
};
-static const struct dc_link_settings link_training_fallback_table[] = {
-/* 4320 Mbytes/sec*/
-{ LANE_COUNT_FOUR, LINK_RATE_HIGH3, LINK_SPREAD_DISABLED },
-/* 2160 Mbytes/sec*/
-{ LANE_COUNT_FOUR, LINK_RATE_HIGH2, LINK_SPREAD_DISABLED },
-/* 1080 Mbytes/sec*/
-{ LANE_COUNT_FOUR, LINK_RATE_HIGH, LINK_SPREAD_DISABLED },
-/* 648 Mbytes/sec*/
-{ LANE_COUNT_FOUR, LINK_RATE_LOW, LINK_SPREAD_DISABLED },
-/* 2160 Mbytes/sec*/
-{ LANE_COUNT_TWO, LINK_RATE_HIGH3, LINK_SPREAD_DISABLED },
-/* 1080 Mbytes/sec*/
-{ LANE_COUNT_TWO, LINK_RATE_HIGH2, LINK_SPREAD_DISABLED },
-/* 540 Mbytes/sec*/
-{ LANE_COUNT_TWO, LINK_RATE_HIGH, LINK_SPREAD_DISABLED },
-/* 324 Mbytes/sec*/
-{ LANE_COUNT_TWO, LINK_RATE_LOW, LINK_SPREAD_DISABLED },
-/* 1080 Mbytes/sec*/
-{ LANE_COUNT_ONE, LINK_RATE_HIGH3, LINK_SPREAD_DISABLED },
-/* 540 Mbytes/sec*/
-{ LANE_COUNT_ONE, LINK_RATE_HIGH2, LINK_SPREAD_DISABLED },
-/* 270 Mbytes/sec*/
-{ LANE_COUNT_ONE, LINK_RATE_HIGH, LINK_SPREAD_DISABLED },
-/* 162 Mbytes/sec*/
-{ LANE_COUNT_ONE, LINK_RATE_LOW, LINK_SPREAD_DISABLED } };
-
static void wait_for_training_aux_rd_interval(
struct core_link* link,
uint32_t default_wait_in_micro_secs)
@@ -1053,29 +1027,6 @@ bool perform_link_training_with_retries(
return false;
}
-/*TODO add more check to see if link support request link configuration */
-static bool is_link_setting_supported(
- const struct dc_link_settings *link_setting,
- const struct dc_link_settings *max_link_setting)
-{
- if (link_setting->lane_count > max_link_setting->lane_count ||
- link_setting->link_rate > max_link_setting->link_rate)
- return false;
- return true;
-}
-
-static const uint32_t get_link_training_fallback_table_len(
- struct core_link *link)
-{
- return ARRAY_SIZE(link_training_fallback_table);
-}
-
-static const struct dc_link_settings *get_link_training_fallback_table(
- struct core_link *link, uint32_t i)
-{
- return &link_training_fallback_table[i];
-}
-
static struct dc_link_settings get_max_link_cap(struct core_link *link)
{
/* Set Default link settings */
@@ -1284,6 +1235,32 @@ enum dc_link_rate reduce_link_rate(enum dc_link_rate link_rate)
}
}
+enum dc_lane_count increase_lane_count(enum dc_lane_count lane_count)
+{
+ switch (lane_count) {
+ case LANE_COUNT_ONE:
+ return LANE_COUNT_TWO;
+ case LANE_COUNT_TWO:
+ return LANE_COUNT_FOUR;
+ default:
+ return LANE_COUNT_UNKNOWN;
+ }
+}
+
+enum dc_link_rate increase_link_rate(enum dc_link_rate link_rate)
+{
+ switch (link_rate) {
+ case LINK_RATE_LOW:
+ return LINK_RATE_HIGH;
+ case LINK_RATE_HIGH:
+ return LINK_RATE_HIGH2;
+ case LINK_RATE_HIGH2:
+ return LINK_RATE_HIGH3;
+ default:
+ return LINK_RATE_UNKNOWN;
+ }
+}
+
/*
* function: set link rate and lane count fallback based
* on current link setting and last link training result
@@ -1463,57 +1440,60 @@ void decide_link_settings(struct core_stream *stream,
struct dc_link_settings *link_setting)
{
- const struct dc_link_settings *cur_ls;
+ struct dc_link_settings initial_link_setting = {
+ LANE_COUNT_ONE, LINK_RATE_LOW, LINK_SPREAD_DISABLED};
+ struct dc_link_settings current_link_setting =
+ initial_link_setting;
struct core_link* link;
uint32_t req_bw;
uint32_t link_bw;
- uint32_t i;
req_bw = bandwidth_in_kbps_from_timing(
&stream->public.timing);
+ link = stream->sink->link;
+
/* if preferred is specified through AMDDP, use it, if it's enough
* to drive the mode
*/
- link = stream->sink->link;
-
- if ((link->public.reported_link_cap.lane_count != LANE_COUNT_UNKNOWN) &&
- (link->public.reported_link_cap.link_rate <=
- link->public.verified_link_cap.link_rate)) {
+ if (link->public.preferred_link_setting.lane_count !=
+ LANE_COUNT_UNKNOWN &&
+ link->public.preferred_link_setting.link_rate !=
+ LINK_RATE_UNKNOWN) {
+ *link_setting = link->public.preferred_link_setting;
+ return;
+ }
+ /* search for the minimum link setting that:
+ * 1. is supported according to the link training result
+ * 2. could support the b/w requested by the timing
+ */
+ while (current_link_setting.link_rate <=
+ link->public.max_link_setting.link_rate) {
link_bw = bandwidth_in_kbps_from_link_settings(
- &link->public.reported_link_cap);
-
- if (req_bw < link_bw) {
- *link_setting = link->public.reported_link_cap;
+ ¤t_link_setting);
+ if (req_bw <= link_bw) {
+ *link_setting = current_link_setting;
return;
}
- }
- /* search for first suitable setting for the requested
- * bandwidth
- */
- for (i = 0; i < get_link_training_fallback_table_len(link); i++) {
-
- cur_ls = get_link_training_fallback_table(link, i);
-
- link_bw =
- bandwidth_in_kbps_from_link_settings(
- cur_ls);
-
- if (req_bw < link_bw) {
- if (is_link_setting_supported(
- cur_ls,
- &link->public.max_link_setting)) {
- *link_setting = *cur_ls;
- return;
- }
+ if (current_link_setting.lane_count <
+ link->public.max_link_setting.lane_count) {
+ current_link_setting.lane_count =
+ increase_lane_count(
+ current_link_setting.lane_count);
+ } else {
+ current_link_setting.link_rate =
+ increase_link_rate(
+ current_link_setting.link_rate);
+ current_link_setting.lane_count =
+ initial_link_setting.lane_count;
}
}
BREAK_TO_DEBUGGER();
ASSERT(link->public.verified_link_cap.lane_count !=
- LANE_COUNT_UNKNOWN);
+ LANE_COUNT_UNKNOWN);
*link_setting = link->public.verified_link_cap;
}
diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index 617270829936..ee04c3562081 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -674,6 +674,7 @@ struct dc_link {
struct dc_link_settings max_link_setting;
struct dc_link_settings cur_link_settings;
struct dc_lane_settings cur_lane_setting;
+ struct dc_link_settings preferred_link_setting;
uint8_t ddc_hw_inst;
--
2.11.0
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