e4cf6580ac
If a Setup packet is received but yet to DMA out, the controller will not process the End Transfer command of any endpoint. Polling of its DEPCMD.CmdAct may block setting up TRB for Setup packet, causing a command timeout. This may occur if the driver doesn’t service the completion interrupt of the control status stage yet due to system latency, then it won’t prepare TRB and start the transfer for the next Setup Stage. To the host side, the control transfer had completed, and the host can send a new Setup packet at this point. In the meanwhile, if the driver receives an async call to dequeue a request (triggering End Transfer) to any endpoint, then the driver will service that End transfer first, blocking the control status stage completion handler. Since no TRB is available for the Setup stage, the Setup packet can’t be DMA’ed out and the End Transfer gets hung. The driver must not block setting up of the Setup stage. So track and only issue the End Transfer command only when there’s Setup TRB prepared so that the controller can DMA out the Setup packet. Delay the End transfer command if there's no Setup TRB available. This is applicable to all DWC_usb3x IPs. Co-developed-by: Wesley Cheng <quic_wcheng@quicinc.com> Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com> Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com> Link: https://lore.kernel.org/r/20220309205402.4467-1-quic_wcheng@quicinc.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.