88b1bb1f3b
Currently the link_state is uninitialized and the default value is 0(U0) before the first time we start the udc, and after we start the udc then stop the udc, the link_state will be undefined. We may have the following warnings if we start the udc again with an undefined link_state: WARNING: CPU: 0 PID: 327 at drivers/usb/dwc3/gadget.c:294 dwc3_send_gadget_ep_cmd+0x304/0x308 dwc3 100e0000.hidwc3_0: wakeup failed --> -22 [...] Call Trace: [<c010f270>] (unwind_backtrace) from [<c010b3d8>] (show_stack+0x10/0x14) [<c010b3d8>] (show_stack) from [<c034a4dc>] (dump_stack+0x84/0x98) [<c034a4dc>] (dump_stack) from [<c0118000>] (__warn+0xe8/0x100) [<c0118000>] (__warn) from [<c0118050>](warn_slowpath_fmt+0x38/0x48) [<c0118050>] (warn_slowpath_fmt) from [<c0442ec0>](dwc3_send_gadget_ep_cmd+0x304/0x308) [<c0442ec0>] (dwc3_send_gadget_ep_cmd) from [<c0445e68>](dwc3_ep0_start_trans+0x48/0xf4) [<c0445e68>] (dwc3_ep0_start_trans) from [<c0446750>](dwc3_ep0_out_start+0x64/0x80) [<c0446750>] (dwc3_ep0_out_start) from [<c04451c0>](__dwc3_gadget_start+0x1e0/0x278) [<c04451c0>] (__dwc3_gadget_start) from [<c04452e0>](dwc3_gadget_start+0x88/0x10c) [<c04452e0>] (dwc3_gadget_start) from [<c045ee54>](udc_bind_to_driver+0x88/0xbc) [<c045ee54>] (udc_bind_to_driver) from [<c045f29c>](usb_gadget_probe_driver+0xf8/0x140) [<c045f29c>] (usb_gadget_probe_driver) from [<bf005424>](gadget_dev_desc_UDC_store+0xac/0xc4 [libcomposite]) [<bf005424>] (gadget_dev_desc_UDC_store [libcomposite]) from[<c023d8e0>] (configfs_write_file+0xd4/0x160) [<c023d8e0>] (configfs_write_file) from [<c01d51e8>] (__vfs_write+0x1c/0x114) [<c01d51e8>] (__vfs_write) from [<c01d5ff4>] (vfs_write+0xa4/0x168) [<c01d5ff4>] (vfs_write) from [<c01d6d40>] (SyS_write+0x3c/0x90) [<c01d6d40>] (SyS_write) from [<c0107400>] (ret_fast_syscall+0x0/0x3c) Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> |
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.