25b6ee378d
commit 3b8070335f751aac9f1526ae2e012e6f5b8b0f21 upstream.
The OPAL NVRAM driver does not sleep in case it gets OPAL_BUSY or
OPAL_BUSY_EVENT from firmware, which causes large scheduling
latencies, and various lockup errors to trigger (again, BMC reboot
can cause it).
Fix this by converting it to the standard form OPAL_BUSY loop that
sleeps.
Fixes: 628daa8d5abf ("powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks")
Depends-on: 34dd25de9fe3 ("powerpc/powernv: define a standard delay for OPAL_BUSY type retry loops")
Cc: stable@vger.kernel.org # v3.2+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.