On 10/27/15 20:09, Thomas Monjalon wrote: > Any Follow-up to this discussion? > Should we mark this patch as rejected?
Hmmm... This patch fixes an obvious spec violation. Why would it be rejected? > > 2015-08-24 11:11, Vlad Zolotarov: >> On 08/20/15 18:37, Vlad Zolotarov wrote: >>> According to 82599 and x540 HW specifications RS bit *must* be >>> set in the last descriptor of *every* packet. >>> >>> Before this patch there were 3 types of Tx callbacks that were setting >>> RS bit every tx_rs_thresh descriptors. This patch introduces a set of >>> new callbacks, one for each type mentioned above, that will set the RS >>> bit in every EOP descriptor. >>> >>> ixgbe_set_tx_function() will set the appropriate Tx callback according >>> to the device family. >> [+Jesse and Jeff] >> >> I've started to look at the i40e PMD and it has the same RS bit >> deferring logic >> as ixgbe PMD has (surprise, surprise!.. ;)). To recall, i40e PMD uses a >> descriptor write-back >> completion mode. >> >> From the HW Spec it's unclear if RS bit should be set on *every* descriptor >> with EOP bit. However I noticed that Linux driver, before it moved to >> HEAD write-back mode, was setting RS >> bit on every EOP descriptor. >> >> So, here is a question to Intel guys: could u, pls., clarify this point? >> >> Thanks in advance, >> vlad > >
