From 4496363bec32df36df51db7f915a11d3b38615e3 Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Mon, 3 Aug 2020 21:32:16 +0100 Subject: [PATCH] sfc_ef100: fail the probe if NIC uses unsol_ev credits In the future, EF100 is planned to have a credit-based scheme for handling unsolicited events, which drivers will need to use in order to function correctly. However, current EF100 hardware does not yet generate unsolicited events and the credit scheme has not yet been implemented in firmware. To prevent compatibility problems later if the current driver is used with future firmware which does implement it, we check for the corresponding capability flag (which that future firmware will set), and if found, we refuse to probe. Signed-off-by: Edward Cree Signed-off-by: David S. Miller --- drivers/net/ethernet/sfc/ef100_nic.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/ethernet/sfc/ef100_nic.c b/drivers/net/ethernet/sfc/ef100_nic.c index 75131bcf4f1a..c2bec2bdbc1f 100644 --- a/drivers/net/ethernet/sfc/ef100_nic.c +++ b/drivers/net/ethernet/sfc/ef100_nic.c @@ -602,6 +602,12 @@ static int ef100_probe_main(struct efx_nic *efx) goto fail; } + if (efx_has_cap(efx, UNSOL_EV_CREDIT_SUPPORTED)) { + netif_info(efx, drv, efx->net_dev, "Firmware uses unsolicited-event credits\n"); + rc = -EINVAL; + goto fail; + } + rc = ef100_phy_probe(efx); if (rc) goto fail;