[RFC PATCH 1/3] chelsio: cxgb: Remove ndo_poll_controller()

Ahmed S. Darwish
2020-12-24T13:12:52Z

Since commit ac3d9dd034e5 ("netpoll: make ndo_poll_controller()
optional"), networking drivers which use NAPI for clearing their TX
completions should not provide an ndo_poll_controller(). Netpoll simply
triggers the necessary TX queues cleanup by synchronously calling the
driver's NAPI poll handler -- with irqs off and a zero budget.

Modify the cxgb's poll method to clear the TX queues upon zero budget.
Per API requirements, make sure to never consume any RX packet in that
case (budget=0), and thus also not to increment the budget upon return.

Afterwards, remove ndo_poll_controller().

Link: https://lkml.kernel.org/r/20180921222752.101307-1-edumazet@google.com
Link: https://lkml.kernel.org/r/A782704A-DF97-4E85-B10A-D2268A67DFD7@fb.com
References: 822d54b9c2c1 ("netpoll: Drop budget parameter from NAPI polling call hierarchy")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Cc: Eric Dumazet <edumazet@google.com>
---
drivers/net/ethernet/chelsio/cxgb/cxgb2.c | 14 --------------
drivers/net/ethernet/chelsio/cxgb/sge.c | 9 ++++++++-
2 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb/cxgb2.c b/drivers/net/ethernet/chelsio/cxgb/cxgb2.c
index 0e4a0f413960..7b5a98330ef7 100644
--- a/drivers/net/ethernet/chelsio/cxgb/cxgb2.c
+++ b/drivers/net/ethernet/chelsio/cxgb/cxgb2.c
@@ -878,17 +878,6 @@ static int t1_set_features(struct net_device *dev, netdev_features_t features)

return 0;
}
-#ifdef CONFIG_NET_POLL_CONTROLLER
-static void t1_netpoll(struct net_device *dev)
-{
- unsigned long flags;
- struct adapter *adapter = dev->ml_priv;
-
- local_irq_save(flags);
- t1_interrupt(adapter->pdev->irq, adapter);
- local_irq_restore(flags);
-}
-#endif

/*
* Periodic accumulation of MAC statistics. This is used only if the MAC
@@ -973,9 +962,6 @@ static const struct net_device_ops cxgb_netdev_ops = {
.ndo_set_mac_address = t1_set_mac_addr,
.ndo_fix_features = t1_fix_features,
.ndo_set_features = t1_set_features,
-#ifdef CONFIG_NET_POLL_CONTROLLER
- .ndo_poll_controller = t1_netpoll,
-#endif
};

static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
diff --git a/drivers/net/ethernet/chelsio/cxgb/sge.c b/drivers/net/ethernet/chelsio/cxgb/sge.c
index 2d9c2b5a690a..d6df1a87db0b 100644
--- a/drivers/net/ethernet/chelsio/cxgb/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb/sge.c
@@ -1609,7 +1609,14 @@ static int process_pure_responses(struct adapter *adapter)
int t1_poll(struct napi_struct *napi, int budget)
{
struct adapter *adapter = container_of(napi, struct adapter, napi);
- int work_done = process_responses(adapter, budget);
+ int work_done = 0;
+
+ if (budget)
+ work_done = process_responses(adapter, budget);
+ else {
+ /* budget=0 means: don't poll rx data */
+ process_pure_responses(adapter);
+ }

if (likely(work_done < budget)) {
napi_complete_done(napi, work_done);
--
2.29.2