mirror of
https://github.com/rd-stuffs/msm-4.14.git
synced 2025-02-20 11:45:48 +08:00
8f472434b8
[ Upstream commit ceb94bc52c437463f0903e61060a94a2226fb672 ] This patch adds a safety connection way for "forced_b_device" with "workaround_for_vbus" like below: < Example for R-Car E3 Ebisu > # modprobe <any usb gadget driver> # echo 1 > /sys/kernel/debug/ee020000.usb/b_device (connect a usb cable to host side.) # echo 2 > /sys/kernel/debug/ee020000.usb/b_device Previous code should have connected a usb cable before the "b_device" is set to 1 on the Ebisu board. However, if xHCI driver on the board is probed, it causes some troubles: - Conflicts USB VBUS/signals between the board and another host. - "Cannot enable. Maybe the USB cable is bad?" might happen on both the board and another host with a usb hub. - Cannot enumerate a usb gadget correctly because an interruption of VBUS change happens unexpectedly. Reported-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.