This is a note to let you know that I've just added the patch titled IB/hfi1: Allow larger MTU without AIP to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ib-hfi1-allow-larger-mtu-without-aip.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit bb274dfb10c090fe7b8d1f7afed32f2360b8e32c Author: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxxxxxxxxxxxxx> Date: Tue Feb 8 14:25:09 2022 -0500 IB/hfi1: Allow larger MTU without AIP [ Upstream commit b135e324d7a2e7fa0a7ef925076136e799b79f44 ] The AIP code signals the phys_mtu in the following query_port() fragment: props->phys_mtu = HFI1_CAP_IS_KSET(AIP) ? hfi1_max_mtu : ib_mtu_enum_to_int(props->max_mtu); Using the largest MTU possible should not depend on AIP. Fix by unconditionally using the hfi1_max_mtu value. Fixes: 6d72344cf6c4 ("IB/ipoib: Increase ipoib Datagram mode MTU's upper limit") Link: https://lore.kernel.org/r/1644348309-174874-1-git-send-email-mike.marciniszyn@xxxxxxxxxxxxxxxxxxxx Reviewed-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/infiniband/hw/hfi1/verbs.c b/drivers/infiniband/hw/hfi1/verbs.c index 26bea51869bf..ef8e0bdacb51 100644 --- a/drivers/infiniband/hw/hfi1/verbs.c +++ b/drivers/infiniband/hw/hfi1/verbs.c @@ -1397,8 +1397,7 @@ static int query_port(struct rvt_dev_info *rdi, u32 port_num, 4096 : hfi1_max_mtu), IB_MTU_4096); props->active_mtu = !valid_ib_mtu(ppd->ibmtu) ? props->max_mtu : mtu_to_enum(ppd->ibmtu, IB_MTU_4096); - props->phys_mtu = HFI1_CAP_IS_KSET(AIP) ? hfi1_max_mtu : - ib_mtu_enum_to_int(props->max_mtu); + props->phys_mtu = hfi1_max_mtu; return 0; }