From: Jeff Kirsher Date: Fri, 03 Apr 2015 14:06:18 -0700 Subject: [Intel-wired-lan] [net-next 20/25] fm10k: Add support for ITR scaling based on PCIe link speed In-Reply-To: <1428092835-16834-20-git-send-email-jeffrey.t.kirsher@intel.com> References: <1428092835-16834-1-git-send-email-jeffrey.t.kirsher@intel.com> <1428092835-16834-20-git-send-email-jeffrey.t.kirsher@intel.com> Message-ID: <1428095178.2662.131.camel@jtkirshe-mobl> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: On Fri, 2015-04-03 at 13:27 -0700, Jeff Kirsher wrote: > Fm10k's interrupt throttle timers are based on the PCIe link > speed. Because of this, the value being programmed into the ITR > registers must be scaled. > > For the PF, this is as simple as reading the PCIe link speed and > storing > the result. However, in the case of SR-IOV, the VF's interrupt > throttle > timers are based on the link speed of the PF. However, the VF is > unable > to get the link speed information from its configuration space, so the > PF must inform it of what scale to use. > > Rather than pass this scale via mailbox message, take advantage of > unused bits in the TDLEN register to pass the scale. It is the > responsibility of the PF to program this for the VF while setting up > the > VF queues and the responsibility of the VF to get the information > accordingly. This is preferable because it allows the VF to set up the > interrupts properly during initialization and matches how the MAC > address is passed in the TDBAL/TDBAH registers. > > Signed-off-by: Jeff Kirsher > Signed-off-by: Jacob Keller > Signed-off-by: Matthew Vick > --- > drivers/net/ethernet/intel/fm10k/fm10k.h | 4 ++++ > drivers/net/ethernet/intel/fm10k/fm10k_main.c | 17 +++++++++++++---- > drivers/net/ethernet/intel/fm10k/fm10k_pci.c | 12 ++++++++++-- > drivers/net/ethernet/intel/fm10k/fm10k_pf.c | 16 +++++++++++++++- > drivers/net/ethernet/intel/fm10k/fm10k_type.h | 6 ++++++ > drivers/net/ethernet/intel/fm10k/fm10k_vf.c | 11 +++++++++-- > 6 files changed, 57 insertions(+), 9 deletions(-) I have applied to my queue. -- git://git.kernel.org/pub/scm/linux/kernel/git/jkirsher/next-queue.git dev-queue -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: This is a digitally signed message part URL: