On 15/02/2025 22:04, Dmitry Osipenko wrote:

From: Shreeya Patel <redacted>

Add initial support for the Synopsys DesignWare HDMI RX
Controller Driver used by Rockchip RK3588. The driver
supports:
 - HDMI 1.4b and 2.0 modes (HDMI 4k@60Hz)
 - RGB888, YUV422, YUV444 and YCC420 pixel formats
 - CEC
 - EDID configuration

The hardware also has Audio and HDCP capabilities, but these are
not yet supported by the driver.

Co-developed-by: Dingxian Wen <redacted>
Signed-off-by: Dingxian Wen <redacted>
Signed-off-by: Shreeya Patel <redacted>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/media/platform/Kconfig                |    1 +
 drivers/media/platform/Makefile               |    1 +
 drivers/media/platform/synopsys/Kconfig       |    3 +
 drivers/media/platform/synopsys/Makefile      |    2 +
 .../media/platform/synopsys/hdmirx/Kconfig    |   27 +
 .../media/platform/synopsys/hdmirx/Makefile   |    4 +
 .../platform/synopsys/hdmirx/snps_hdmirx.c    | 2715 +++++++++++++++++
 .../platform/synopsys/hdmirx/snps_hdmirx.h    |  394 +++
 .../synopsys/hdmirx/snps_hdmirx_cec.c         |  284 ++
 .../synopsys/hdmirx/snps_hdmirx_cec.h         |   44 +
 10 files changed, 3475 insertions(+)
 create mode 100644 drivers/media/platform/synopsys/Kconfig
 create mode 100644 drivers/media/platform/synopsys/Makefile
 create mode 100644 drivers/media/platform/synopsys/hdmirx/Kconfig
 create mode 100644 drivers/media/platform/synopsys/hdmirx/Makefile
 create mode 100644 drivers/media/platform/synopsys/hdmirx/snps_hdmirx.c
 create mode 100644 drivers/media/platform/synopsys/hdmirx/snps_hdmirx.h
 create mode 100644 drivers/media/platform/synopsys/hdmirx/snps_hdmirx_cec.c
 create mode 100644 drivers/media/platform/synopsys/hdmirx/snps_hdmirx_cec.h

<snip>

+static ssize_t
+hdmirx_debugfs_if_read(u32 type, void *priv, struct file *filp,
+		       char __user *ubuf, size_t count, loff_t *ppos)
+{
+	struct snps_hdmirx_dev *hdmirx_dev = priv;
+	u8 aviif[3 + 7 * 4];
+	int len;
+
+	if (type != V4L2_DEBUGFS_IF_AVI)
+		return 0;
+
+	hdmirx_read_avi_infoframe(hdmirx_dev, aviif);
+
+	len = simple_read_from_buffer(ubuf, count, ppos,
+				      aviif, ARRAY_SIZE(aviif));
+
+	return len < 0 ? 0 : len;
+}

Have you tested this with 'edid-decode -c -I /path/to/avi'? Also test that it is
empty if there is no AVI InfoFrame (e.g. when there is no incoming video). I don't see
a test for that in the code.

I also see no sanity check regarding the length of the InfoFrame, it just outputs
the full array, meaning you get padding as well since the AVI InfoFrame is smaller
than ARRAY_SIZE(aviif). In fact, edid-decode will fail about that if the -c option
is used.

See tc358743_debugfs_if_read of how this is typically handled.

Regards,

	Hans