All of lore.kernel.org
 help / color / mirror / Atom feed
* [Intel-gfx] [PATCH] drm/i915/dp: Add missing TPS4 programming bits
@ 2021-07-19 23:59 Khaled Almahallawy
  2021-07-20  0:19 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for " Patchwork
                   ` (4 more replies)
  0 siblings, 5 replies; 8+ messages in thread
From: Khaled Almahallawy @ 2021-07-19 23:59 UTC (permalink / raw)
  To: intel-gfx

Bits 20:19 are used to set CP2520 Patterns 1/2/3 (refer to Specs:50484).
TPS4 is CP2520 Pattern 3 (refer to DP2.0 spaces Table 3-11, DPCD 00248h
LINK_QUAL_PATTERN_SELECT, and DP PHY 1.4 CTS - Appendix A - Compliance
EYE Pattern(CP2520; Normative))

For TPS4, setting bits 20:19 to value != 00b, leads to a non-TPS4 pattern.
This is confirmed using DP Scope running DP1.4 PHY CTS.

To avoid any accidental wrong setting of bits 20:19, set it correctly for
TPS4 LT pattern selection. This programming sequence is the same used by EV.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
CC: José Roberto de Souza <jose.souza@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Khaled Almahallawy <khaled.almahallawy@intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c | 2 ++
 drivers/gpu/drm/i915/i915_reg.h          | 4 ++++
 2 files changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 26a3aa73fcc4..54b4b28fdc74 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -3412,6 +3412,8 @@ static void intel_ddi_set_link_train(struct intel_dp *intel_dp,
 		break;
 	case DP_TRAINING_PATTERN_4:
 		temp |= DP_TP_CTL_LINK_TRAIN_PAT4;
+		temp &= ~DP_TP_CTL_TRAIN_PAT4_SEL_MASK;
+		temp |= DP_TP_CTL_TRAIN_PAT4_SEL_TP4a;
 		break;
 	}
 
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 943fe485c662..a65998df9994 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -10176,6 +10176,10 @@ enum skl_power_gate {
 #define  DP_TP_CTL_MODE_SST			(0 << 27)
 #define  DP_TP_CTL_MODE_MST			(1 << 27)
 #define  DP_TP_CTL_FORCE_ACT			(1 << 25)
+#define  DP_TP_CTL_TRAIN_PAT4_SEL_MASK		(3 << 19)
+#define  DP_TP_CTL_TRAIN_PAT4_SEL_TP4a		(0 << 19)
+#define  DP_TP_CTL_TRAIN_PAT4_SEL_TP4b		(1 << 19)
+#define  DP_TP_CTL_TRAIN_PAT4_SEL_TP4c		(2 << 19)
 #define  DP_TP_CTL_ENHANCED_FRAME_ENABLE	(1 << 18)
 #define  DP_TP_CTL_FDI_AUTOTRAIN		(1 << 15)
 #define  DP_TP_CTL_LINK_TRAIN_MASK		(7 << 8)
-- 
2.25.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

^ permalink raw reply related	[flat|nested] 8+ messages in thread
end of thread, other threads:[~2021-10-20 22:18 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-19 23:59 [Intel-gfx] [PATCH] drm/i915/dp: Add missing TPS4 programming bits Khaled Almahallawy
2021-07-20  0:19 ` [Intel-gfx] ✗ Fi.CI.CHECKPATCH: warning for " Patchwork
2021-07-20  0:24 ` [Intel-gfx] ✗ Fi.CI.DOCS: " Patchwork
2021-07-20  0:46 ` [Intel-gfx] ✓ Fi.CI.BAT: success " Patchwork
2021-07-20  3:15 ` [Intel-gfx] ✓ Fi.CI.IGT: " Patchwork
2021-10-19 11:52 ` [Intel-gfx] [PATCH] " Jani Nikula
2021-10-19 12:01   ` Ville Syrjälä
2021-10-20 22:18     ` Almahallawy, Khaled

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.