On Mon, 1 Jun 2026, Kandpal, Suraj wrote:
Subject: [PATCH v4 06/10] drm/i915/buf_trans: abstract VS/PE-O access and
index computation
Lay into intel_ddi_buf_trans_get() infrastructure for VS/PE-O.
Add (*get_phy_vspeo_index)() function hook into struct intel_encoder.
This function pointer is responsible for computing index of requested table
from VBT #57.
Add also (*get_phy_vspeo)() function hook into struct intel_encoder.
This function pointer will be the accessor which parses and sets port's buffer
basing on VBT #57's data.
Note that these two pointer need to be separate since they are taking place
during two different abstraction layers: (*get_phy_vspeo_index()) operates on
crtc_state, while (*get_phy_vspeo)() consumes devdata.
Add generic function pointer indicating lack of VS/PE-O's support.
Signed-off-by: Michał Grzelak <[email protected]>
---
.../drm/i915/display/intel_ddi_buf_trans.c | 30 ++++++++++++++++++-
.../drm/i915/display/intel_display_types.h | 5 ++++
2 files changed, 34 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c
b/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c
index 4cd1e4d76c7a..fbd5efc5ca6c 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c
@@ -1784,10 +1784,20 @@ xe3plpd_get_lt_buf_trans(struct intel_encoder
*encoder,
return intel_get_buf_trans(&xe3plpd_lt_trans_dp14,
n_entries); }
+static int
+_get_phy_vspeo_index(struct intel_encoder *encoder,
+ const struct intel_crtc_state *crtc_state) {
+ return -EOPNOTSUPP;
+}
+
void intel_ddi_buf_trans_init(struct intel_encoder *encoder) {
struct intel_display *display = to_intel_display(encoder);
+ encoder->get_phy_vspeo_index = _get_phy_vspeo_index;
+ encoder->get_phy_vspeo = NULL;
+
if (HAS_LT_PHY(display)) {
encoder->get_buf_trans = xe3plpd_get_lt_buf_trans;
} else if (DISPLAY_VER(display) >= 14) { @@ -1857,5 +1867,23 @@
const struct intel_ddi_buf_trans *intel_ddi_buf_trans_get(struct
intel_encoder *
const struct
intel_crtc_state *crtc_state,
int *n_entries)
{
- return encoder->get_buf_trans(encoder, crtc_state, n_entries);
+ struct intel_display *display = to_intel_display(encoder);
+ const struct intel_ddi_buf_trans *buf_trans;
+ bool vspeo;
+ int table;
+
+ vspeo = intel_bios_encoder_requests_vspeo(encoder->devdata);
+ if (!vspeo)
+ return encoder->get_buf_trans(encoder, crtc_state,
n_entries);
+
+ table = encoder->get_phy_vspeo_index(encoder, crtc_state);
+ if (table < 0) {
+ drm_WARN_ONCE(display->drm, 1,
+ "platform does not support VS/PE-O, setting
default\n");
+
WARN does not belong here maybe a drm_dbg_kms() saying "VBT requests vspeo but does
not provide index table"
The reason being panel vendors may have broken VBT requesting for VS/PE but not
providing a table.
This will just cause Alarms to go off in CI, where you will be debugging broken
VBTs which wont be fixed specially for the older
Generations.
I agree that drm_dbg_kms() would suffice. I'm not sure on the phrasing
though. Current patch series does not support DKL nor MG PHY, and this
message was targeted to be shown when eg. TGL's DKL requests Override
when there is no code to handle it.
Now I think that probably it would be better to do what you have already
said [1], that the debug message should be issued only when VS/PE-O would
successfully take place, instead of spamming it all along the way.
BR,
Michał
[1]
https://lore.kernel.org/intel-gfx/dm3ppf208195d8d13e4abb86f46cce9999be3...@dm3ppf208195d8d.namprd11.prod.outlook.com/
Regards,
Suraj Kandpal
+ return encoder->get_buf_trans(encoder, crtc_state,
n_entries);
+ }
+
+ buf_trans = encoder->get_phy_vspeo(encoder->devdata, table);
+ return intel_get_buf_trans(buf_trans, n_entries);
}
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
b/drivers/gpu/drm/i915/display/intel_display_types.h
index c21e0c0ef0b1..829e17fbfb0a 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -292,6 +292,11 @@ struct intel_encoder {
void (*set_signal_levels)(struct intel_encoder *encoder,
const struct intel_crtc_state *crtc_state);
+ int (*get_phy_vspeo_index)(struct intel_encoder *encoder,
+ const struct intel_crtc_state *crtc_state);
+ const struct intel_ddi_buf_trans *(*get_phy_vspeo)(const struct
intel_bios_encoder_data *devdata,
+ int idx);
+
enum hpd_pin hpd_pin;
enum intel_display_power_domain power_domain;
--
2.45.2
