On 7/31/2025 10:46 AM, Suraj Kandpal wrote:
Add a function that helps identify if the rate provided needs to
be overridden. For this we need a function that compares the rate
provided and bitmask of rates provided in VBT.
--v2
-Rename functions [Jani]
-Return the mask instead of parsing it in function [Jani]
-Move the declaration in header [Jani]
Signed-off-by: Suraj Kandpal <suraj.kand...@intel.com>
---
drivers/gpu/drm/i915/display/intel_bios.c | 29 +++++++++++++++++++++++
drivers/gpu/drm/i915/display/intel_bios.h | 2 ++
2 files changed, 31 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_bios.c
b/drivers/gpu/drm/i915/display/intel_bios.c
index 8337ebe0f2c8..7adb7c4b0432 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -2480,6 +2480,25 @@ static int parse_bdb_216_dp_max_link_rate(const int
vbt_max_link_rate)
}
}
+static u32 edp_rate_override_mask(int rate)
+{
+ switch (rate) {
+ case 2000000: return BDB_263_VBT_EDP_LINK_RATE_20;
+ case 1350000: return BDB_263_VBT_EDP_LINK_RATE_13_5;
+ case 1000000: return BDB_263_VBT_EDP_LINK_RATE_10;
+ case 810000: return BDB_263_VBT_EDP_LINK_RATE_8_1;
+ case 675000: return BDB_263_VBT_EDP_LINK_RATE_6_75;
+ case 540000: return BDB_263_VBT_EDP_LINK_RATE_5_4;
+ case 432000: return BDB_263_VBT_EDP_LINK_RATE_4_32;
+ case 324000: return BDB_263_VBT_EDP_LINK_RATE_3_24;
+ case 270000: return BDB_263_VBT_EDP_LINK_RATE_2_7;
+ case 243000: return BDB_263_VBT_EDP_LINK_RATE_2_43;
+ case 216000: return BDB_263_VBT_EDP_LINK_RATE_2_16;
+ case 162000: return BDB_263_VBT_EDP_LINK_RATE_1_62;
+ default: return 0;
+ }
+}
+
int intel_bios_dp_max_link_rate(const struct intel_bios_encoder_data *devdata)
{
if (!devdata || devdata->display->vbt.version < 216)
@@ -2499,6 +2518,16 @@ int intel_bios_dp_max_lane_count(const struct
intel_bios_encoder_data *devdata)
return devdata->child.dp_max_lane_count + 1;
}
+bool
+intel_bios_encoder_supports_edp_rate(const struct intel_bios_encoder_data
*devdata,
+ int rate)
+{
+ if (!devdata || devdata->display->vbt.version < 263)
+ return false;
+
+ return devdata->child.edp_data_rate_override &
edp_rate_override_mask(rate);
The function name intel_bios_encoder_supports_edp_rate() suggests that
it returns true if a given eDP rate is supported.
However, the current implementation returns true when the corresponding
bit is set in edp_data_rate_override,
which actually indicates that the rate is rejected.
To avoid confusion, either the function should be renamed to
intel_bios_encoder_rejects_edp_rate()
to reflect its actual behavior, or the logic should be inverted so that
the function returns true
only when the rate is acceptable.
Regards,
Ankit
+}
+
static void sanitize_device_type(struct intel_bios_encoder_data *devdata,
enum port port)
{
diff --git a/drivers/gpu/drm/i915/display/intel_bios.h
b/drivers/gpu/drm/i915/display/intel_bios.h
index 6cd7a011b8c4..a4abaa89a682 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.h
+++ b/drivers/gpu/drm/i915/display/intel_bios.h
@@ -251,6 +251,8 @@ bool intel_bios_encoder_supports_dvi(const struct
intel_bios_encoder_data *devda
bool intel_bios_encoder_supports_hdmi(const struct intel_bios_encoder_data
*devdata);
bool intel_bios_encoder_supports_dp(const struct intel_bios_encoder_data
*devdata);
bool intel_bios_encoder_supports_edp(const struct intel_bios_encoder_data
*devdata);
+bool intel_bios_encoder_supports_edp_rate(const struct intel_bios_encoder_data
*devdata,
+ int rate);
bool intel_bios_encoder_supports_typec_usb(const struct
intel_bios_encoder_data *devdata);
bool intel_bios_encoder_supports_tbt(const struct intel_bios_encoder_data
*devdata);
bool intel_bios_encoder_supports_dsi(const struct intel_bios_encoder_data
*devdata);
