Commit b356dac8 authored by Mitch Williams's avatar Mitch Williams Committed by Jeff Kirsher
Browse files

i40e: avoid divide by zero 



In some weird circumstances with DCB enabled, the firmware can fail to
configure the VSI, leaving us with zero traffic classes. Check for this
state when we configure RSS to avoid a panic.

Signed-off-by: default avatarMitch Williams <mitch.a.williams@intel.com>
Tested-by: default avatarAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
parent e3a5d6e6

drivers/net/ethernet/intel/i40e/i40e_main.c

+7 −2
Original line number Diff line number Diff line
@@ -10783,8 +10783,13 @@ static int i40e_pf_config_rss(struct i40e_pf *pf) 
	/* Determine the RSS size of the VSI */

	if (!vsi->rss_size) {

		u16 qcount;



		qcount = vsi->num_queue_pairs / vsi->tc_config.numtc;

		/* If the firmware does something weird during VSI init, we

		 * could end up with zero TCs. Check for that to avoid

		 * divide-by-zero. It probably won't pass traffic, but it also

		 * won't panic.

		 */

		qcount = vsi->num_queue_pairs /

			 (vsi->tc_config.numtc ? vsi->tc_config.numtc : 1);

		vsi->rss_size = min_t(int, pf->alloc_rss_size, qcount);

	}

	if (!vsi->rss_size)

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