On 2016年04月28日 20:21, Felipe Balbi wrote:
I also attach git log of system/core/adb/usb_linux_client.cpp of Android N for your reference. " Author: Badhri Jagan Sridharan <Badhri@xxxxxxxxxx> Date: Mon Oct 5 13:04:03 2015 -0700 adbd: Add os descriptor support for adb. Eventhough windows does not rely on extended os descriptor for adbd, when android usb device is configures as a composite device such as mtp+adb, windows discards the extended os descriptor even if one of the USB function fails to send the extended compat descriptor. This results in automatic install of MTP driverto fail when Android device is in "File Transfer" mode with adb enabled. https://msdn.microsoft.com/en-us/library/windows/hardware/gg463179.aspx "Okay, cool. Can you check that you're limitting your controller's speed to high-speed ?
Let's focus on original patch. Could you help to explain why we need below d->Reserved1 checking? Now the question is that https://msdn.microsoft.com/en-us/library/windows/hardware/gg463179.aspx Page 7 of OS_Desc_CompatID.doc defines reserved field to be 1 and below code will think that os_desc is invalid because d->Reserved1 is 1. In f_fs.c " static int __ffs_data_do_os_desc(enum ffs_os_desc_type type, struct usb_os_desc_header *h, void *data, unsigned len, void *priv) { struct ffs_data *ffs = priv; u8 length; ENTER(); switch (type) { case FFS_OS_DESC_EXT_COMPAT: { struct usb_ext_compat_desc *d = data; int i; if (len < sizeof(*d) || d->bFirstInterfaceNumber >= ffs->interfaces_count || d->Reserved1) return -EINVAL; " --nvpublic -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
