USB: add quirk to avoid config and interface strings

Apparently the Configuration and Interface strings aren't used as
often as the Vendor, Product, and Serial strings.  In at least one
device (a Saitek Cyborg Gold 3D joystick), attempts to read the
Configuration string cause the device to stop responding to Control
requests.

This patch (as1226) adds a quirks flag, telling the kernel not to
read a device's Configuration or Interface strings, together with a
new quirk for the offending joystick.

Reported-by: Melchior FRANZ <melchior.franz@gmail.com>
Tested-by: Melchior FRANZ <melchior.franz@gmail.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>  [2.6.28 and 2.6.29, nothing earlier]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 49e7f56..3922fa9 100644 (file)
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1719,7 +1719,8 @@ free_interfaces:
        }
        kfree(new_interfaces);
 
-       if (cp->string == NULL)
+       if (cp->string == NULL &&
+                       !(dev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
                cp->string = usb_cache_string(dev, cp->desc.iConfiguration);
 
        /* Now that all the interfaces are set up, register them

diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index c070b34..ab93918 100644 (file)
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -54,6 +54,10 @@ static const struct usb_device_id usb_quirk_list[] = {
        { USB_DEVICE(0x0638, 0x0a13), .driver_info =
          USB_QUIRK_STRING_FETCH_255 },
 
+       /* Saitek Cyborg Gold Joystick */
+       { USB_DEVICE(0x06a3, 0x0006), .driver_info =
+                       USB_QUIRK_CONFIG_INTF_STRINGS },
+
        /* M-Systems Flash Disk Pioneers */
        { USB_DEVICE(0x08ec, 0x1000), .driver_info = USB_QUIRK_RESET_RESUME },
 

diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 4cc2456..c667891 100644 (file)
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -13,6 +13,7 @@
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/usb.h>
+#include <linux/usb/quirks.h>
 #include "usb.h"
 
 /* Active configuration fields */
@@ -813,7 +814,8 @@ int usb_create_sysfs_intf_files(struct usb_interface *intf)
        if (intf->sysfs_files_created || intf->unregistering)
                return 0;
 
-       if (alt->string == NULL)
+       if (alt->string == NULL &&
+                       !(udev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
                alt->string = usb_cache_string(udev, alt->desc.iInterface);
        if (alt->string)
                retval = device_create_file(&intf->dev, &dev_attr_interface);

diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h
index 7f6c603..2526f3b 100644 (file)
--- a/include/linux/usb/quirks.h
+++ b/include/linux/usb/quirks.h
@@ -16,4 +16,7 @@
 /* device can't handle Set-Interface requests */
 #define USB_QUIRK_NO_SET_INTF          0x00000004
 
+/* device can't handle its Configuration or Interface strings */
+#define USB_QUIRK_CONFIG_INTF_STRINGS  0x00000008
+
 #endif /* __LINUX_USB_QUIRKS_H */