[PATCH v3 4/4] drm/i915: Show bios vbt when read from firmware/spi/oprom

[Radhakrishna Sripada]

Make debugfs vbt only shows valid vbt when read from ACPI opregion.
Make it work when read from firmware/spi/pci oprom cases.

v2: Protect sysfs write with vbt check

Cc: Jani Nikula <jani.nikula at intel.com>
Signed-off-by: Radhakrishna Sripada <radhakrishna.sripada at intel.com>
---
 drivers/gpu/drm/i915/display/intel_bios.c | 24 ++++++++++++++++++-----
 1 file changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index 4cd338ed362d..a9c71afab5e7 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -3723,15 +3723,29 @@ static int intel_bios_vbt_show(struct seq_file *m, void *unused)
 	struct drm_i915_private *i915 = m->private;
 	const void *vbt;
 	size_t vbt_size;
+	bool need_cleanup = false;
+
+	vbt = firmware_get_vbt(i915, &vbt_size);
+
+	if (!vbt)
+		vbt = intel_opregion_get_vbt(i915, &vbt_size);
+
+	if (!vbt && IS_DGFX(i915)) {
+		vbt = spi_oprom_get_vbt(i915, &vbt_size);
+		need_cleanup = true;
+	}
+
+	if (!vbt) {
+		vbt = oprom_get_vbt(i915, &vbt_size);
+		need_cleanup = true;
+	}
 
-	/*
-	 * FIXME: VBT might originate from other places than opregion, and then
-	 * this would be incorrect.
-	 */
-	vbt = intel_opregion_get_vbt(i915, &vbt_size);
 	if (vbt)
 		seq_write(m, vbt, vbt_size);
 
+	if (need_cleanup)
+		kfree(vbt);
+
 	return 0;
 }
 
-- 
2.34.1