0001-usb-request-on-8-bytes-for-USB_SPEED_FULL-bMaxPacket.patch

gistfile1.txt

From df9e5b78687fc4eed4988f99d3f195cba8b227e1 Mon Sep 17 00:00:00 2001
From: Janne Grunau <j@jannau.net>
Date: Fri, 26 Aug 2022 00:01:15 +0200
Subject: [PATCH 1/1] usb: request on 8 bytes for USB_SPEED_FULL
 bMaxPacketSize0 probing

Fixes probing of Logitech Unifying receivers (bcdDevice 12.03 or 12.10)
with bMaxPacketSize0 == 8 on Apple silicon SoCs using DWC3 controllers.

Signed-off-by: Janne Grunau <j@jannau.net>
---
 common/usb.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/common/usb.c b/common/usb.c
index aad13fd9c557..2d6d782f9103 100644
--- a/common/usb.c
+++ b/common/usb.c
@@ -999,8 +999,17 @@ static int usb_setup_descriptor(struct usb_device *dev, bool do_read)
                 * the number of packets in addition to the number of bytes.
                 * A request for 64 bytes of data with the maxpacket guessed
                 * as 64 (above) yields a request for 1 packet.
+                *
+                * The DWC3 controller integrated into Apple silicon SoCs like
+                * the M1 and M2 does not like to read 64 bytes for devices with
+                * bMaxPacketSize0 == 8. request only 8 bytes which should also
+                * result in a single packet.
+                * Fixes probing errors with Logitech Unifying receivers with
+                * bcdDevice 12.03 or 12.10.
+                * A delay of 1 ms after this get_descriptor_len() call fixes
+                * the issue as well.
                 */
-               err = get_descriptor_len(dev, 64, 8);
+               err = get_descriptor_len(dev, 8, 8);
                if (err)
                        return err;
        }
-- 
2.35.1