efx_probe_filters() has not been called yet when EF100 calls into
 efx_mcdi_filter_table_probe(), for which it wants to take the
 filter_sem.
Fixes: a9dc3d5612ce ("sfc_ef100: RX filter table management and related gubbins")
Signed-off-by: Edward Cree <ecree@solarflare.com>
Link: https://lore.kernel.org/r/24fad43e-887d-051e-25e3-506f23f63abf@solarflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 
        efx->num_mac_stats = MC_CMD_MAC_NSTATS;
        BUILD_BUG_ON(MC_CMD_MAC_NSTATS - 1 != MC_CMD_MAC_GENERATION_END);
        mutex_init(&efx->mac_lock);
+       init_rwsem(&efx->filter_sem);
 #ifdef CONFIG_RFS_ACCEL
        mutex_init(&efx->rps_mutex);
        spin_lock_init(&efx->rps_hash_lock);
 
 {
        int rc;
 
-       init_rwsem(&efx->filter_sem);
        mutex_lock(&efx->mac_lock);
        down_write(&efx->filter_sem);
        rc = efx->type->filter_table_probe(efx);