fce7bbcd07
commit f88359e1588b85cf0e8209ab7d6620085f3441d9 upstream. From: John Stultz <john.stultz@linaro.org> According to the programming guide, to switch mode for DRD controller, the driver needs to do the following. To switch from device to host: 1. Reset controller with GCTL.CoreSoftReset 2. Set GCTL.PrtCapDir(host mode) 3. Reset the host with USBCMD.HCRESET 4. Then follow up with the initializing host registers sequence To switch from host to device: 1. Reset controller with GCTL.CoreSoftReset 2. Set GCTL.PrtCapDir(device mode) 3. Reset the device with DCTL.CSftRst 4. Then follow up with the initializing registers sequence Currently we're missing step 1) to do GCTL.CoreSoftReset and step 3) of switching from host to device. John Stult reported a lockup issue seen with HiKey960 platform without these steps[1]. Similar issue is observed with Ferry's testing platform[2]. So, apply the required steps along with some fixes to Yu Chen's and John Stultz's version. The main fixes to their versions are the missing wait for clocks synchronization before clearing GCTL.CoreSoftReset and only apply DCTL.CSftRst when switching from host to device. [1] https://lore.kernel.org/linux-usb/20210108015115.27920-1-john.stultz@linaro.org/ [2] https://lore.kernel.org/linux-usb/0ba7a6ba-e6a7-9cd4-0695-64fc927e01f1@gmail.com/ Fixes: 41ce1456e1db ("usb: dwc3: core: make dwc3_set_mode() work properly") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Ferry Toth <fntoth@gmail.com> Cc: Wesley Cheng <wcheng@codeaurora.org> Cc: <stable@vger.kernel.org> Tested-by: John Stultz <john.stultz@linaro.org> Tested-by: Wesley Cheng <wcheng@codeaurora.org> Signed-off-by: Yu Chen <chenyu56@huawei.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Link: https://lore.kernel.org/r/374440f8dcd4f06c02c2caf4b1efde86774e02d9.1618521663.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.