While performing HDMI compliance testing, test equipment may request
different bpc output for signal measurement. However, display driver
typically determines the maximum available bpc based on HW bandwidth.
Introduce a new debugfs that allows user to configure dedicated bpc
manually, and making HDMI compliance test much easier.
v2: Using exist variable max_requested_bpc.
Cc: Shankar Uma <uma.shan...@intel.com>
Cc: Jani Nikula <jani.nik...@intel.com>
Cc: Imre Deak <imre.d...@intel.com>
Cc: Vidya Srinivas <vidya.srini...@intel.com>
Signed-off-by: Lee Shawn C <shawn.c....@intel.com>
---
.../drm/i915/display/intel_display_debugfs.c | 46 +++++++++++++++++++
1 file changed, 46 insertions(+)
diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
index ce3f9810c42d..5ef2bcffefc5 100644
--- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
+++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
@@ -1208,6 +1208,47 @@ static const struct file_operations
i915_dsc_fractional_bpp_fops = {
.write = i915_dsc_fractional_bpp_write
};
+static int i915_force_bpc_show(struct seq_file *m, void *data)
+{
+ struct intel_connector *connector = m->private;
+ struct drm_connector *conn = &connector->base;
+
+ seq_printf(m, "%u\n", conn->state->max_requested_bpc);
+
+ return 0;
+}
+
+static ssize_t i915_force_bpc_write(struct file *file,
+ const char __user *ubuf,
+ size_t len, loff_t *offp)
+{
+ struct seq_file *m = file->private_data;
+ struct intel_connector *connector = m->private;
+ struct intel_display *display = to_intel_display(connector);
+ struct drm_connector *conn = &connector->base;
+ int new_bpc, ret;
+
+ ret = kstrtoint_from_user(ubuf, len, 0, &new_bpc);
+ if (ret < 0)
+ return ret;
+
+ switch (new_bpc) {
+ case 8:
+ case 10:
+ case 12:
+ break;
+ default:
+ drm_dbg_kms(display->drm, "Invalid bpc value (%u)\n", new_bpc);
+ return -EINVAL;
+ }
+
+ conn->state->max_requested_bpc = new_bpc;
+
+ *offp += len;
+ return len;
+}
+DEFINE_SHOW_STORE_ATTRIBUTE(i915_force_bpc);
+
/*
* Returns the Current CRTC's bpc.
* Example usage: cat /sys/kernel/debug/dri/0/crtc-0/i915_current_bpc
@@ -1359,6 +1400,11 @@ void intel_connector_debugfs_add(struct intel_connector
*connector)
connector_type == DRM_MODE_CONNECTOR_HDMIB)
debugfs_create_file("i915_lpsp_capability", 0444, root,
connector, &i915_lpsp_capability_fops);
+
+ if (connector_type == DRM_MODE_CONNECTOR_HDMIA ||
+ connector_type == DRM_MODE_CONNECTOR_HDMIB)
+ debugfs_create_file("i915_force_bpc", 0644, root,
+ connector, &i915_force_bpc_fops);
}
/**
--
2.34.1
