Since EHCI/OHCI controllers on R-Car Gen3 SoCs are possible to be getting stuck very rarely after a full/low usb device was disconnected. To detect/recover from such a situation, the controllers require a special way which poll the EHCI PORTSC register and changes the OHCI functional state. So, this patch adds a polling timer into the ehci-platform driver, and if the ehci driver detects the issue by the EHCI PORTSC register, the ehci driver removes a companion device (= the OHCI controller) to change the OHCI functional state to USB Reset once. And then, the ehci driver adds the companion device again. Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/1580114262-25029-1-git-send-email-yoshihiro.shimoda.uh@renesas.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.
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