On Fri, 2017-03-03 at 00:58:44 UTC, Balbir Singh wrote: > CPPR (Current Processor Priority Register) emulation on icp-opal > uses a single priority in the backend and that can cause CPU > hotplug to be affected when we try to send an IPI to it. > > The fix is in migrate_irqs_away, the fix does the following: > > 1. It moves the setting of CPPR to after all IRQ migration > is complete > 2. In icp-opal, we ignore masking the CPPR when the CPPR > is set to default priority, anything else we just pass > through > > Right now this fix is designed with backporting to stable > in mind > > We'll need a newer version of this later when we merge the > DEFAULT and IPI priorities to the same value in the kernel. > > Fixes: d74361881f0d ("powerpc/xics: Add ICP OPAL backend") > Cc: sta...@vger.kernel.org (v4.8+) > > Testing > > 1. I've tested this fix on a virtual partition running under > kvm > 2. Gautham and Vaidy have done some testing on an system that > uses the OPAL backend > 3. I've also tested this on a system with a native XICS controller > > Suggested-by: Michael Ellerman <m...@ellerman.id.au> > Reported-by: Vaidyanathan Srinivasan <sva...@linux.vnet.ibm.com> > Tested-by: Vaidyanathan Srinivasan <sva...@linux.vnet.ibm.com> > Signed-off-by: Balbir Singh <bsinghar...@gmail.com>
Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/a69e2fb70350a66f91175cd2625f1e cheers