On 12/22/2017 11:53 AM, Jason Gunthorpe wrote:
On Fri, Dec 22, 2017 at 08:47:20AM -0800, Dennis Dalessandro wrote:
From: Michael J. Ruhl michael.j.ruhl@intel.com
During driver init, various registers are saved to allow restoration after an FLR or gen3 bump. Some of these registers are not available in some circumstances (i.e. Virtual machines).
Delete unnecessary register read/write, and only access register if the capability exists.
Cc: stable@vger.kernel.org # 4.14.x Fixes: a618b7e40af2 ("IB/hfi1: Move saving PCI values to a separate function") Reviewed-by: Mike Marciniszyn mike.marciniszyn@intel.com Signed-off-by: Michael J. Ruhl michael.j.ruhl@intel.com Signed-off-by: Dennis Dalessandro dennis.dalessandro@intel.com drivers/infiniband/hw/hfi1/hfi.h | 1 - drivers/infiniband/hw/hfi1/pcie.c | 30 ++++++++++++------------------ 2 files changed, 12 insertions(+), 19 deletions(-)
Since we are getting late in the RC cycle can you help me clarify the user visible bug here? No need to resend
I'm guessing when hfi1 is used in a virtual machine with passthrough (SRIOV?) it fails in ?? way?
Ugh. I actually amended the commit message to include a blurb on the impact. Sorry about that, not sure what happened. It should have had this line of text:
" Without this patch the driver will not load on a virtual machine. "
So basically we just don't work on VMs. There is no panic or anything. I was on the fence whether it could go for this late of an -rc or not.
-Denny