[Qemu-devel] [PATCH 0/3] usb-host: some little tweaks to hopefully reduce usb pass-through problems.

[Qemu-devel] [PATCH 0/3] usb-host: some little tweaks to hopefully reduce usb pass-through problems.

[Gerd Hoffmann]

Gerd Hoffmann (3):
  usb: call reset handler before updating state
  usb-host: skip reset for untouched devices
  usb-host: avoid libusb_set_configuration calls

 hw/usb/core.c        |  2 +-
 hw/usb/host-libusb.c | 21 +++++++++++++--------
 2 files changed, 14 insertions(+), 9 deletions(-)

-- 
2.18.1

[Qemu-devel] [PATCH 1/3] usb: call reset handler before updating state

[Gerd Hoffmann]

That way the device reset handler can see what
the before-reset state of the device is.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/usb/core.c b/hw/usb/core.c
index 8fbd9c7d573b..3ab48a16074b 100644
--- a/hw/usb/core.c
+++ b/hw/usb/core.c
@@ -87,10 +87,10 @@ void usb_device_reset(USBDevice *dev)
     if (dev == NULL || !dev->attached) {
         return;
     }
+    usb_device_handle_reset(dev);
     dev->remote_wakeup = 0;
     dev->addr = 0;
     dev->state = USB_STATE_DEFAULT;
-    usb_device_handle_reset(dev);
 }
 
 void usb_wakeup(USBEndpoint *ep, unsigned int stream)
-- 
2.18.1

[Qemu-devel] [PATCH 2/3] usb-host: skip reset for untouched devices

[Gerd Hoffmann]

If the guest didn't talk to the device yet, skip the reset.
Without this usb-host devices get resetted a number of times
at boot time for no good reason.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/usb/host-libusb.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c
index 67b7465915f5..4e9a45a5d26f 100644
--- a/hw/usb/host-libusb.c
+++ b/hw/usb/host-libusb.c
@@ -1459,6 +1459,9 @@ static void usb_host_handle_reset(USBDevice *udev)
     if (!s->allow_guest_reset) {
         return;
     }
+    if (udev->addr == 0) {
+        return;
+    }
 
     trace_usb_host_reset(s->bus_num, s->addr);
 
-- 
2.18.1

[Qemu-devel] [PATCH 3/3] usb-host: avoid libusb_set_configuration calls

[Gerd Hoffmann]

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 --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) {
-- 
2.18.1