[PATCH 2/5] usb: wait after initial device descriptor read

[Ahmad Fatoum <a.fatoum@barebox.org>]

Port over U-Boot commit 3406e9d8afcc8ade8cb3e697be2bcf9cc85c9d04:

|   usb: Add 1ms delay after first Get Descriptor request
|
|   Logitech Unifying Receiver 046d:c52b bcdDevice 12.10 seems
|   sensitive about the first Get Descriptor request. If there
|   are any other requests in the same microframe, the device
|   reports bogus data, first of the descriptor parts is not
|   sent to the host. Wait over one microframe duration before
|   issuing subsequent requests to avoid probe failure with
|   this device, since it can be used to connect USB keyboards.
|
|   Signed-off-by: Marek Vasut <marex@denx.de>
|   Tested-by: Janne Grunau <j@jannau.net>

Assisted-by: Codex:gpt-5.5
Signed-off-by: Ahmad Fatoum <a.fatoum@barebox.org>
---
 drivers/usb/core/usb.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index ae87137447c7..c6b3187de17d 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -403,6 +403,17 @@ static int usb_setup_descriptor(struct usb_device *dev, bool do_read)
 		if (err)
 			return err;
 
+		/*
+		 * Logitech Unifying Receiver 046d:c52b bcdDevice 12.10 seems
+		 * sensitive about the first Get Descriptor request. If there
+		 * are any other requests in the same microframe, the device
+		 * reports bogus data, first of the descriptor parts is not
+		 * sent to the host. Wait over one microframe duration here
+		 * (1mS for USB 1.x , 125uS for USB 2.0) to avoid triggering
+		 * the issue.
+		 */
+		mdelay(1);
+
 		dev->epmaxpacketin[0] = dev->descriptor->bMaxPacketSize0;
 		dev->epmaxpacketout[0] = dev->descriptor->bMaxPacketSize0;
 	}
-- 
2.47.3