[PATCH] USB: serial: pl2303: fix HX type detection

Johan Hovold
2021-07-30T12:23:37Z

The device release number for HX-type devices is configurable in
EEPROM/OTPROM and cannot be used reliably for type detection.

Assume all (non-H) devices with bcdUSB 1.1 and unknown bcdDevice to be
of HX type while adding a bcdDevice check for HXD and TB (1.1 and 2.0,
respectively).

Reported-by: Chris <chris@cyber-anlage.de>
Fixes: 8a7bf7510d1f ("USB: serial: pl2303: amend and tighten type detection")
Cc: stable@vger.kernel.org # 5.13
Signed-off-by: Johan Hovold <johan@kernel.org>
---
drivers/usb/serial/pl2303.c | 41 ++++++++++++++++++++++---------------
1 file changed, 25 insertions(+), 16 deletions(-)

diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index 2f2f5047452b..17601e32083e 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -418,24 +418,33 @@ static int pl2303_detect_type(struct usb_serial *serial)
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;
+ switch (bcdUSB) {
+ case 0x110:
+ switch (bcdDevice) {
+ case 0x300:
+ return TYPE_HX;
+ case 0x400:
+ return TYPE_HXD;
+ default:
+ return TYPE_HX;
+ }
break;
- case 0x300:
- if (bcdUSB == 0x200)
+ case 0x200:
+ switch (bcdDevice) {
+ case 0x100:
+ /*
+ * Assume it's an HXN-type if the device doesn't
+ * support the old read request value.
+ */
+ if (!pl2303_supports_hx_status(serial))
+ return TYPE_HXN;
+ break;
+ case 0x300:
return TYPE_TA;
-
- return TYPE_HX;
- case 0x400:
- return TYPE_HXD;
- case 0x500:
- return TYPE_TB;
+ case 0x500:
+ return TYPE_TB;
+ }
+ break;
}

dev_err(&serial->interface->dev,
--
2.31.1