From bfe44898848614cfcb3a269bc965afbe1f0f331c Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Wed, 22 May 2019 11:47:02 +0200
Subject: [PATCH] usb-host: avoid libusb_set_configuration calls
Seems some devices become confused when we call
libusb_set_configuration(). So before calling the function check
whenever the device has multiple configurations in the first place, and
in case it hasn't (which is the case for the majority of devices) simply
skip the call as it will have no effect anyway.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20190522094702.17619-4-kraxel@redhat.com
---
hw/usb/host-libusb.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c
index 4e9a45a5d2..4f765d7f9a 100644
--- a/hw/usb/host-libusb.c
+++ b/hw/usb/host-libusb.c
@@ -1225,19 +1225,21 @@ static void usb_host_set_address(USBHostDevice *s, int addr)
static void usb_host_set_config(USBHostDevice *s, int config, USBPacket *p)
{
- int rc;
+ int rc = 0;
trace_usb_host_set_config(s->bus_num, s->addr, config);
usb_host_release_interfaces(s);
- rc = libusb_set_configuration(s->dh, config);
- if (rc != 0) {
- usb_host_libusb_error("libusb_set_configuration", rc);
- p->status = USB_RET_STALL;
- if (rc == LIBUSB_ERROR_NO_DEVICE) {
- usb_host_nodev(s);
+ if (s->ddesc.bNumConfigurations != 1) {
+ rc = libusb_set_configuration(s->dh, config);
+ if (rc != 0) {
+ usb_host_libusb_error("libusb_set_configuration", rc);
+ p->status = USB_RET_STALL;
+ if (rc == LIBUSB_ERROR_NO_DEVICE) {
+ usb_host_nodev(s);
+ }
+ return;
}
- return;
}
p->status = usb_host_claim_interfaces(s, config);
if (p->status != USB_RET_SUCCESS) {
--
2.30.2