sfc: Validate IRQ moderation parameters in efx_init_irq_moderation()

Add a range check, and move the check that RX and TX are consistent
from efx_ethtool_set_coalesce().

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/falcon.c b/drivers/net/ethernet/sfc/falcon.c
index 94bf4aaf984d..4dd1748a19c6 100644
--- a/drivers/net/ethernet/sfc/falcon.c
+++ b/drivers/net/ethernet/sfc/falcon.c
@@ -104,6 +104,8 @@ static void falcon_push_irq_moderation(struct efx_channel *channel)
         efx_dword_t timer_cmd;
         struct efx_nic *efx = channel->efx;
 
+        BUILD_BUG_ON(EFX_IRQ_MOD_MAX > (1 << FRF_AB_TC_TIMER_VAL_WIDTH));
+
         /* Set timer register */
         if (channel->irq_moderation) {
                 EFX_POPULATE_DWORD_2(timer_cmd,