From: Andrew Kephart <akephart@xxxxxxxxxxxx>
For at least one DisplayLink device, the vendor-specific information can
be found in the config descriptor instead of as a separate, device-level
descriptor. This patch searches the current interface (of the current
config descriptor) for the DL vendor-specific descriptor.
Signed-off-by: Andrew Kephart <akephart@xxxxxxxxxxxx>
Signed-off-by: Bernie Thompson <bernie@xxxxxxxxxxxx>
---
drivers/video/udlfb.c | 21 ++++++++++++++++-----
1 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/drivers/video/udlfb.c b/drivers/video/udlfb.c
index 844b371..bdd21de 100644
--- a/drivers/video/udlfb.c
+++ b/drivers/video/udlfb.c
@@ -1489,21 +1489,30 @@ static int dlfb_select_std_channel(struct dlfb_data *dev)
}
static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev,
- struct usb_device *usbdev)
+ struct usb_interface *interface)
{
char *desc;
char *buf;
char *desc_end;
- u8 total_len = 0;
+ int total_len = 0;
buf = kzalloc(MAX_VENDOR_DESCRIPTOR_SIZE, GFP_KERNEL);
if (!buf)
return false;
desc = buf;
- total_len = usb_get_descriptor(usbdev, 0x5f, /* vendor specific */
- 0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
+ total_len = usb_get_descriptor(interface_to_usbdev(interface),
+ 0x5f, /* vendor specific */
+ 0, desc, MAX_VENDOR_DESCRIPTOR_SIZE);
+
+ /* if not found, look in configuration descriptor */
+ if (total_len < 0) {
+ if (0 == usb_get_extra_descriptor(interface->cur_altsetting,
+ 0x5f, &desc))
+ total_len = (int) desc[0];
+ }
+
if (total_len > 5) {
pr_info("vendor descriptor length:%x data:%02x %02x %02x %02x" \
"%02x %02x %02x %02x %02x %02x %02x\n",
@@ -1544,6 +1553,8 @@ static int dlfb_parse_vendor_descriptor(struct dlfb_data *dev,
}
desc += length;
}
+ } else {
+ pr_info("vendor descriptor not available (%d)\n", total_len);
}
goto success;
@@ -1593,7 +1604,7 @@ static int dlfb_usb_probe(struct usb_interface *interface,
dev->sku_pixel_limit = 2048 * 1152; /* default to maximum */
- if (!dlfb_parse_vendor_descriptor(dev, usbdev)) {
+ if (!dlfb_parse_vendor_descriptor(dev, interface)) {
pr_err("firmware not recognized. Assume incompatible device\n");
goto error;
}
--
1.7.4.1
--
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