diff mbox series

[3/3] usb-host: avoid libusb_set_configuration calls

Message ID 20190522094702.17619-4-kraxel@redhat.com
State New
Headers show
Series usb-host: some little tweaks to hopefully reduce usb pass-through problems. | expand

Commit Message

Gerd Hoffmann May 22, 2019, 9:47 a.m. UTC 
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>
---
 hw/usb/host-libusb.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)
diff mbox series

Patch

diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c
index 4e9a45a5d26f..4f765d7f9a2f 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) {