drivers/gpu/drm/udl/udl_edid.c

Source file repositories/reference/linux-study-clean/drivers/gpu/drm/udl/udl_edid.c

File Facts

System
Linux kernel
Corpus path
drivers/gpu/drm/udl/udl_edid.c
Extension
.c
Size
1711 bytes
Lines
82
Domain
Driver Families
Bucket
drivers/gpu
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (ret < 0) {
			drm_err(dev, "Read EDID byte %zu failed err %x\n", i, ret);
			goto err_drm_dev_exit;
		} else if (ret < 1) {
			ret = -EIO;
			drm_err(dev, "Read EDID byte %zu failed\n", i);
			goto err_drm_dev_exit;
		}

		buf[i] = read_buff[1];
	}

	drm_dev_exit(idx);
	kfree(read_buff);

	return 0;

err_drm_dev_exit:
	drm_dev_exit(idx);
err_kfree:
	kfree(read_buff);
	return ret;
}

bool udl_probe_edid(struct udl_device *udl)
{
	u8 hdr[8];
	int ret;

	ret = udl_read_edid_block(udl, hdr, 0, sizeof(hdr));
	if (ret)
		return false;

	/*
	 * The adapter sends all-zeros if no monitor has been
	 * connected. We consider anything else a connection.
	 */
	return !mem_is_zero(hdr, sizeof(hdr));
}

const struct drm_edid *udl_edid_read(struct drm_connector *connector)
{
	struct udl_device *udl = to_udl(connector->dev);

	return drm_edid_read_custom(connector, udl_read_edid_block, udl);
}

Annotation

Implementation Notes