From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bowers, AndrewX Date: Mon, 23 Sep 2019 18:12:34 +0000 Subject: [Intel-wired-lan] [next PATCH S10 07/10] i40e: initialize ITRN registers with correct values In-Reply-To: <20190920091724.51767-7-alice.michael@intel.com> References: <20190920091724.51767-1-alice.michael@intel.com> <20190920091724.51767-7-alice.michael@intel.com> Message-ID: <3503235df4f64fd9bd4efa8da66f3d03@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: > -----Original Message----- > From: Intel-wired-lan [mailto:intel-wired-lan-bounces at osuosl.org] On > Behalf Of Alice Michael > Sent: Friday, September 20, 2019 2:17 AM > To: Michael, Alice ; intel-wired- > lan at lists.osuosl.org > Subject: [Intel-wired-lan] [next PATCH S10 07/10] i40e: initialize ITRN > registers with correct values > > From: Nicholas Nunley > > Since commit 92418fb14750 ("i40e/i40evf: Use usec value instead of reg value > for ITR defines") the driver tracks the interrupt throttling intervals in single > usec units, although the actual ITRN/ITR0 registers are programmed in 2 usec > units. Most register programming flows in the driver correctly handle the > conversion, although it is currently not applied when the registers are > initialized to their default values. Most of the time this doesn't present a > problem since the default values are usually immediately overwritten > through the standard adaptive throttling mechanism, or updated manually by > the user, but if adaptive throttling is disabled and the interval values are left > alone then the incorrect value will persist. > > Since the intended default interval of 50 usecs (vs. 100 usecs as > programmed) performs better for most traffic workloads, this can lead to > performance regressions. > > This patch adds the correct conversion when writing the initial values to the > ITRN registers. > > Signed-off-by: Nicholas Nunley > --- > drivers/net/ethernet/intel/i40e/i40e_main.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) Tested-by: Andrew Bowers