Re: [PATCH for-next v2] RDMA/cma: Fix incorrect Packet Lifetime calculation

From: Jason Gunthorpe <jgg@nvidia.com>
To: "Håkon Bugge" <haakon.bugge@oracle.com>
Cc: Doug Ledford <dledford@redhat.com>,
	Leon Romanovsky <leon@kernel.org>,
	linux-rdma@vger.kernel.org
Subject: Re: [PATCH for-next v2] RDMA/cma: Fix incorrect Packet Lifetime calculation
Date: Fri, 25 Jun 2021 11:44:50 -0300	[thread overview]
Message-ID: <20210625144450.GA3001725@nvidia.com> (raw)
In-Reply-To: <1624371207-26710-1-git-send-email-haakon.bugge@oracle.com>

On Tue, Jun 22, 2021 at 04:13:27PM +0200, Håkon Bugge wrote:
> An approximation for the PacketLifeTime is half the local ACK timeout.
> The encoding for both timers are logarithmic.
> 
> If the local ACK timeout is set, but zero, it means the timer is
> disabled. In this case, we choose the CMA_IBOE_PACKET_LIFETIME value,
> since 50% of infinite makes no sense.
> 
> Before this commit, the PacketLifeTime became 255 if local ACK
> timeout was zero (not running).
> 
> Fixed by explicitly testing for timeout being zero.
> 
> Fixes: e1ee1e62bec4 ("RDMA/cma: Use ACK timeout for RoCE packetLifeTime")
> Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
> Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
> ---
> 
> 	v1 -> v2:
> 	   * Rebased on tip of for-next with ("RDMA/cma: Protect RMW
> 	     with qp_mutex") included
> 	   * A local ACK timeout of zero now sets PacketLifeTime to
>              CMA_IBOE_PACKET_LIFETIME
> 	   * Added Leon's r-b
> ---
>  drivers/infiniband/core/cma.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)

Applied to for-next, thanks

Jason