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[Qemu-devel] [PATCH 02/14] usb-linux: Get the alt. setting from sysfs ra
From: |
Gerd Hoffmann |
Subject: |
[Qemu-devel] [PATCH 02/14] usb-linux: Get the alt. setting from sysfs rather then asking the dev |
Date: |
Wed, 4 May 2011 17:41:36 +0200 |
From: Hans de Goede <address@hidden>
At least one device I have lies when receiving a USB_REQ_GET_INTERFACE,
always returning 0 even if the alternate setting is different. This is
likely caused because in practice this control message is never used as
the operating system's usb stack knows which alternate setting it has
told the device to get into, and thus this ctrl message does not get
tested by device manufacturers.
When usb_fs_type == USB_FS_SYS, the active alt. setting 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: Hans de Goede <address@hidden>
Signed-off-by: Gerd Hoffmann <address@hidden>
---
usb-linux.c | 18 ++++++++++++++++++
1 files changed, 18 insertions(+), 0 deletions(-)
diff --git a/usb-linux.c b/usb-linux.c
index 353e1b1..f4601e6 100644
--- a/usb-linux.c
+++ b/usb-linux.c
@@ -830,6 +830,24 @@ static uint8_t usb_linux_get_alt_setting(USBHostDevice *s,
struct usb_ctrltransfer ct;
int ret;
+ if (usb_fs_type == USB_FS_SYS) {
+ char device_name[64], line[1024];
+ int alt_setting;
+
+ sprintf(device_name, "%d-%d:%d.%d", s->bus_num, s->devpath,
+ (int)configuration, (int)interface);
+
+ if (!usb_host_read_file(line, sizeof(line), "bAlternateSetting",
+ device_name)) {
+ goto usbdevfs;
+ }
+ if (sscanf(line, "%d", &alt_setting) != 1) {
+ goto usbdevfs;
+ }
+ return alt_setting;
+ }
+
+usbdevfs:
ct.bRequestType = USB_DIR_IN | USB_RECIP_INTERFACE;
ct.bRequest = USB_REQ_GET_INTERFACE;
ct.wValue = 0;
--
1.7.1
- [Qemu-devel] [PULL] usb patch queue, Gerd Hoffmann, 2011/05/04
- [Qemu-devel] [PATCH 01/14] usb-linux: introduce a usb_linux_alt_setting function, Gerd Hoffmann, 2011/05/04
- [Qemu-devel] [PATCH 02/14] usb-linux: Get the alt. setting from sysfs rather then asking the dev,
Gerd Hoffmann <=
- [Qemu-devel] [PATCH 07/14] usb-linux: Add support for buffering iso out usb packets, Gerd Hoffmann, 2011/05/04
- [Qemu-devel] [PATCH 03/14] usb-linux: Add support for buffering iso usb packets, Gerd Hoffmann, 2011/05/04
- [Qemu-devel] [PATCH 11/14] ohci: get ohci state via container_of(), Gerd Hoffmann, 2011/05/04
- [Qemu-devel] [PATCH 06/14] usb-linux: We only need to keep track of 15 endpoints, Gerd Hoffmann, 2011/05/04
- [Qemu-devel] [PATCH 04/14] usb-linux: Refuse packets for endpoints which are not in the usb descriptor, Gerd Hoffmann, 2011/05/04
- [Qemu-devel] [PATCH 05/14] usb-linux: Refuse iso packets when max packet size is 0 (alt setting 0), Gerd Hoffmann, 2011/05/04
- [Qemu-devel] [PATCH 10/14] uhci: keep uhci state pointer in async packet struct., Gerd Hoffmann, 2011/05/04
- [Qemu-devel] [PATCH 08/14] usb: control buffer fixes, Gerd Hoffmann, 2011/05/04
- [Qemu-devel] [PATCH 12/14] musb: get musb state via container_of(), Gerd Hoffmann, 2011/05/04
- [Qemu-devel] [PATCH 14/14] usb: mass storage fix, Gerd Hoffmann, 2011/05/04