From 78a7dce49a0e3747e5aab9791434cb71297baf42 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 4 Jun 2019 05:12:46 +0100 Subject: [PATCH 4/5] usb-host: avoid libusb_set_configuration calls MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Gerd Hoffmann Message-id: <20190604051246.11374-5-kraxel@redhat.com> Patchwork-id: 88472 O-Subject: [RHEL-8.1.0 qemu-kvm PATCH 4/4] usb-host: avoid libusb_set_configuration calls Bugzilla: 1719228 RH-Acked-by: Dr. David Alan Gilbert RH-Acked-by: Philippe Mathieu-Daudé RH-Acked-by: Max Reitz 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 Message-id: 20190522094702.17619-4-kraxel@redhat.com (cherry picked from commit bfe44898848614cfcb3a269bc965afbe1f0f331c) Signed-off-by: Danilo C. L. de Paula --- 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 dd3ed02..587ff70 100644 --- a/hw/usb/host-libusb.c +++ b/hw/usb/host-libusb.c @@ -1220,19 +1220,21 @@ 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) { -- 1.8.3.1