Tighten the detection of the new HXN (G) type instead of assuming that
every device which doesn't support the old read request is an HXN.
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/usb/serial/pl2303.c | 32 ++++++++++++++++++++------------
1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index cd2acd8c5246..e742187c8a7f 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -374,12 +374,22 @@ static int pl2303_calc_num_ports(struct usb_serial *serial,
return 1;
}
+static bool pl2303_supports_hx_status(struct usb_serial *serial)
+{
+ int ret;
+ u8 buf;
+
+ ret = usb_control_msg_recv(serial->dev, 0, VENDOR_READ_REQUEST,
+ VENDOR_READ_REQUEST_TYPE, PL2303_READ_TYPE_HX_STATUS,
+ 0, &buf, 1, 100, GFP_KERNEL);
+
+ return ret == 0;
+}
+
static int pl2303_detect_type(struct usb_serial *serial)
{
struct usb_device_descriptor *desc = &serial->dev->descriptor;
u16 bcdDevice, bcdUSB;
- int ret;
- u8 buf;
/*
* Legacy PL2303H, variants 0 and 1 (difference unknown).
@@ -394,20 +404,18 @@ static int pl2303_detect_type(struct usb_serial *serial)
return TYPE_H; /* variant 0 */
}
- /*
- * Assume it's an HXN-type if the device doesn't support the old read
- * request value.
- */
- ret = usb_control_msg_recv(serial->dev, 0, VENDOR_READ_REQUEST,
- VENDOR_READ_REQUEST_TYPE, PL2303_READ_TYPE_HX_STATUS,
- 0, &buf, 1, 100, GFP_KERNEL);
- if (ret)
- return TYPE_HXN;
-
bcdDevice = le16_to_cpu(desc->bcdDevice);
bcdUSB = le16_to_cpu(desc->bcdUSB);
switch (bcdDevice) {
+ case 0x100:
+ /*
+ * Assume it's an HXN-type if the device doesn't support the old read
+ * request value.
+ */
+ if (bcdUSB == 0x200 && !pl2303_supports_hx_status(serial))
+ return TYPE_HXN;
+ break;
case 0x300:
if (bcdUSB == 0x200)
return TYPE_TA;
--
2.26.2
