mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-04-29 15:15:28 -04:00
4d0d7c02df
pnv_wakeup_noloss() expects r12 to contain SRR1 value to determine if the wakeup reason is an HMI in CHECK_HMI_INTERRUPT. When we wakeup with ESL=0, SRR1 will not contain the wakeup reason, so there is no point setting r12 to SRR1. However, we don't set r12 at all so r12 contains garbage (likely a kernel pointer), and is still used to check HMI assuming that it contained SRR1. This causes the OPAL msglog to be filled with the following print: HMI: Received HMI interrupt: HMER = 0x0040000000000000 This patch clears r12 after waking up from stop with ESL=EC=0, so that we don't accidentally enter the HMI handler in pnv_wakeup_noloss() if the value of r12[42:45] corresponds to HMI as wakeup reason. Prior to commit9d29250136("powerpc/64s/idle: Avoid SRR usage in idle sleep/wake paths") this bug existed, in that we would incorrectly look at SRR1 to check for a HMI when SRR1 didn't contain a wakeup reason. However the SRR1 value would just happen to never have bits 42:45 set. Fixes:9d29250136("powerpc/64s/idle: Avoid SRR usage in idle sleep/wake paths") Signed-off-by: Akshay Adiga <akshay.adiga@linux.vnet.ibm.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Change log and comment massaging] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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.