i40e: Do not directly increment Tx next_to_use

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Avoid directly incrementing next_to_use for multiple reasons.  The main
reason being that if we directly increment it then it can attain a state
where it is equal to the ring count.  Technically this is a state it
should not be able to reach but the way this is written it now can.

This patch pulls the value off into a register and then increments it
and writes back either the value or 0 depending on if the value is equal
to the ring count.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

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Alexander Duyck 2013-09-28 06:00:22 +00:00 • committed by Jeff Kirsher

parent 35a1e2ad17

commit fc4ac67bc9

1 changed files with 25 additions and 21 deletions

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drivers/net/ethernet/intel/i40e/i40e_txrx.c

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