From 2cc59d8cb0ebcfa9cf3476c0528e50478997ab0c Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 10 Nov 2010 10:06:25 +0100 Subject: [PATCH] usb-linux: Get the active configuration from sysfs rather then asking the dev Some devices seem to choke on receiving a USB_REQ_GET_CONFIGURATION ctrl msg (witnessed with a digital picture frame usb id 1908:1320). When usb_fs_type == USB_FS_SYS, the active configuration can be read directly from sysfs, which allows using this device through qemu's usb redirection. More in general it seems a good idea to not send needless control msg's to devices, esp. as the code in question is called every time a set_interface is done. Which happens multiple times during virtual machine startup, and when device drivers are activating the usb device. Signed-off-by: Anthony Liguori --- usb-linux.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/usb-linux.c b/usb-linux.c index 111fe1c788..ccf70734e3 100644 --- a/usb-linux.c +++ b/usb-linux.c @@ -152,6 +152,8 @@ static QTAILQ_HEAD(, USBHostDevice) hostdevs = QTAILQ_HEAD_INITIALIZER(hostdevs) static int usb_host_close(USBHostDevice *dev); static int parse_filter(const char *spec, struct USBAutoFilter *f); static void usb_host_auto_check(void *unused); +static int usb_host_read_file(char *line, size_t line_size, + const char *device_file, const char *device_name); static int is_isoc(USBHostDevice *s, int ep) { @@ -781,6 +783,23 @@ static int usb_linux_get_configuration(USBHostDevice *s) struct usb_ctrltransfer ct; int ret; + if (usb_fs_type == USB_FS_SYS) { + char device_name[32], line[1024]; + int configuration; + + sprintf(device_name, "%d-%d", s->bus_num, s->devpath); + + if (!usb_host_read_file(line, sizeof(line), "bConfigurationValue", + device_name)) { + goto usbdevfs; + } + if (sscanf(line, "%d", &configuration) != 1) { + goto usbdevfs; + } + return configuration; + } + +usbdevfs: ct.bRequestType = USB_DIR_IN; ct.bRequest = USB_REQ_GET_CONFIGURATION; ct.wValue = 0;