Lift configuration command from udlfb. If this command is not sent,
then the device never outputs a signal, it's status LED is continually
flashing and occasional "udlfb: wait for urb interrupted" messages are
produced.
Tested with a Rextron VCUD-60 attached to a Thinkpad X201s on Linux 4.7.0
Signed-off-by: Jamie Lentin <jm at lentin.co.uk>
---
This ended up in udl_connector_init() since the name suggests it has
something to do with configuring which output to use, although a quick
search through other displaylink drivers didn't shed any light on what
the bytes in set_def_chn actually mean.
I'm not sure which displaylink chipset the VCUD-60 has, but it's USB ID
is 17e9:0136 if that helps. The vendor descriptor is all 00.
Cheers,
---
drivers/gpu/drm/udl/udl_connector.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/drivers/gpu/drm/udl/udl_connector.c
b/drivers/gpu/drm/udl/udl_connector.c
index 4709b54..2ee8b38 100644
--- a/drivers/gpu/drm/udl/udl_connector.c
+++ b/drivers/gpu/drm/udl/udl_connector.c
@@ -16,6 +16,8 @@
#include <drm/drm_crtc_helper.h>
#include "udl_drv.h"
+#define NR_USB_REQUEST_CHANNEL 0x12
+
/* dummy connector to just get EDID,
all UDL appear to have a DVI-D */
@@ -54,6 +56,26 @@ error:
return NULL;
}
+/*
+ * This is necessary before we can communicate with the display controller.
+ */
+static int udl_select_std_channel(struct udl_device *udl)
+{
+ int ret;
+ u8 set_def_chn[] = {0x57, 0xCD, 0xDC, 0xA7,
+ 0x1C, 0x88, 0x5E, 0x15,
+ 0x60, 0xFE, 0xC6, 0x97,
+ 0x16, 0x3D, 0x47, 0xF2};
+
+ ret = usb_control_msg(udl->udev,
+ usb_sndctrlpipe(udl->udev, 0),
+ NR_USB_REQUEST_CHANNEL,
+ (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
+ set_def_chn, sizeof(set_def_chn),
+ USB_CTRL_SET_TIMEOUT);
+ return ret < 0 ? ret : 0;
+}
+
static int udl_get_modes(struct drm_connector *connector)
{
struct udl_device *udl = connector->dev->dev_private;
@@ -139,6 +161,7 @@ static const struct drm_connector_funcs udl_connector_funcs
= {
int udl_connector_init(struct drm_device *dev, struct drm_encoder *encoder)
{
struct drm_connector *connector;
+ int ret;
connector = kzalloc(sizeof(struct drm_connector), GFP_KERNEL);
if (!connector)
@@ -147,6 +170,10 @@ int udl_connector_init(struct drm_device *dev, struct
drm_encoder *encoder)
drm_connector_init(dev, connector, &udl_connector_funcs,
DRM_MODE_CONNECTOR_DVII);
drm_connector_helper_add(connector, &udl_connector_helper_funcs);
+ ret = udl_select_std_channel(connector->dev->dev_private);
+ if (ret)
+ DRM_ERROR("Selecting channel failed err %x\n", ret);
+
drm_connector_register(connector);
drm_mode_connector_attach_encoder(connector, encoder);
--
2.8.1
