85a087df4a
If the MHI core detects invalid data due to a PCI read, it calls into the controller via link_status() to double check that the link is infact down. All in all, this is pretty pointless, and racy. There are no good reasons for this, and only drawbacks. Its pointless because chances are, the controller is going to do the same thing to determine if the link is down - attempt a PCI access and compare the result. This does not make the link status decision any smarter. Its racy because its possible that the link was down at the time of the MHI core access, but then recovered before the controller access. In this case, the controller will indicate the link is not down, and the MHI core will precede to use a bad value as the MHI core does not attempt to retry the access. Retrying the access in the MHI core is a bad idea because again, it is racy - what if the link is down again? Furthermore, there may be some higher level state associated with the link status, that is now invalid because the link went down. The only reason why the MHI core could see "invalid" data when doing a PCI access, that is actually valid, is if the register actually contained the PCI spec defined sentinel for an invalid access. In this case, it is arguable that the MHI implementation broken, and should be fixed, not worked around. Therefore, remove the link_status() callback before anyone attempts to implement it. Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Reviewed-by: Hemant Kumar <hemantk@codeaurora.org> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Link: https://lore.kernel.org/r/20200430190555.32741-4-manivannan.sadhasivam@linaro.org 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.