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net: Fix new EMAC driver for NAPI changes

PATCH Applied Benjamin Herrenschmidt 2 participants 3 messages Oct 16, 2007 – Oct 17, 2007

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#0 lore raw

PATCH 1/1 net: Fix new EMAC driver for NAPI changes

net: Fix new EMAC driver for NAPI changes

This fixes the new EMAC driver for the NAPI updates. The previous patch by Roland Dreier (already applied) to do that doesn't actually work. This applies on top of it makes it work on my test Ebony machine.

This patch depends on "net: Add __napi_sycnhronize() to sync with napi poll" posted previously.

---

The old EMAC driver does things a bit differently (doesn't do useful locking :-) and seems to work with Roland patch. So I'm not going to touch it unless somebody reports me that it has problems

drivers/net/ibm_newemac/mal.c +17 -8
Index: linux-work/drivers/net/ibm_newemac/mal.c
===================================================================
@@ -45,6 +45,8 @@ int __devinit mal_register_commac(struct
 		return -EBUSY;
 	}
 
+	if (list_empty(&mal->list))
+		napi_enable(&mal->napi);
 	mal->tx_chan_mask |= commac->tx_chan_mask;
 	mal->rx_chan_mask |= commac->rx_chan_mask;
 	list_add(&commac->list, &mal->list);
@@ -67,6 +69,8 @@ void __devexit mal_unregister_commac(str
 	mal->tx_chan_mask &= ~commac->tx_chan_mask;
 	mal->rx_chan_mask &= ~commac->rx_chan_mask;
 	list_del_init(&commac->list);
+	if (list_empty(&mal->list))
+		napi_disable(&mal->napi);
 
 	spin_unlock_irqrestore(&mal->lock, flags);
 }
@@ -182,7 +186,7 @@ static inline void mal_enable_eob_irq(st
 	set_mal_dcrn(mal, MAL_CFG, get_mal_dcrn(mal, MAL_CFG) | MAL_CFG_EOPIE);
 }
 
-/* synchronized by __LINK_STATE_RX_SCHED bit in ndev->state */
+/* synchronized by NAPI state */
 static inline void mal_disable_eob_irq(struct mal_instance *mal)
 {
 	// XXX might want to cache MAL_CFG as the DCR read can be slooooow
@@ -317,8 +321,8 @@ void mal_poll_disable(struct mal_instanc
 	while (test_and_set_bit(MAL_COMMAC_POLL_DISABLED, &commac->flags))
 		msleep(1);
 
-	/* Synchronize with the MAL NAPI poller. */
-	napi_disable(&mal->napi);
+	/* Synchronize with the MAL NAPI poller */
+	__napi_synchronize(&mal->napi);
 }
 
 void mal_poll_enable(struct mal_instance *mal, struct mal_commac *commac)
@@ -326,7 +330,12 @@ void mal_poll_enable(struct mal_instance
 	smp_wmb();
 	clear_bit(MAL_COMMAC_POLL_DISABLED, &commac->flags);
 
-	// XXX might want to kick a poll now...
+	/* Feels better to trigger a poll here to catch up with events that
+	 * may have happened on this channel while disabled. It will most
+	 * probably be delayed until the next interrupt but that's mostly a
+	 * non-issue in the context where this is called.
+	 */
+	napi_schedule(&mal->napi);
 }
 
 static int mal_poll(struct napi_struct *napi, int budget)
@@ -336,8 +345,7 @@ static int mal_poll(struct napi_struct *
 	int received = 0;
 	unsigned long flags;
 
-	MAL_DBG2(mal, "poll(%d) %d ->" NL, *budget,
-		 rx_work_limit);
+	MAL_DBG2(mal, "poll(%d)" NL, budget);
  again:
 	/* Process TX skbs */
 	list_for_each(l, &mal->poll_list) {
@@ -528,11 +536,12 @@ static int __devinit mal_probe(struct of
 	}
 
 	INIT_LIST_HEAD(&mal->poll_list);
-	mal->napi.weight = CONFIG_IBM_NEW_EMAC_POLL_WEIGHT;
-	mal->napi.poll = mal_poll;
 	INIT_LIST_HEAD(&mal->list);
 	spin_lock_init(&mal->lock);
 
+	netif_napi_add(NULL, &mal->napi, mal_poll,
+		       CONFIG_IBM_NEW_EMAC_POLL_WEIGHT);
+
 	/* Load power-on reset defaults */
 	mal_reset(mal);
 
Applied
#1 lore raw
Quoted 9 lines · Benjamin Herrenschmidt

net: Fix new EMAC driver for NAPI changes

This fixes the new EMAC driver for the NAPI updates. The previous patch by Roland Dreier (already applied) to do that doesn't actually work. This applies on top of it makes it work on my test Ebony machine.

This patch depends on "net: Add __napi_sycnhronize() to sync with napi poll" posted previously.

Quoted 6 lines

---

The old EMAC driver does things a bit differently (doesn't do useful locking :-) and seems to work with Roland patch. So I'm not going to touch it unless somebody reports me that it has problems

applied

#2 lore raw
Quoted 10 lines · Jeff Garzik
Quoted 9 lines · Benjamin Herrenschmidt

net: Fix new EMAC driver for NAPI changes

This fixes the new EMAC driver for the NAPI updates. The previous patch by Roland Dreier (already applied) to do that doesn't actually work. This applies on top of it makes it work on my test Ebony machine.

This patch depends on "net: Add __napi_sycnhronize() to sync with napi poll" posted previously.

Quoted 8 lines
Quoted 6 lines

---

The old EMAC driver does things a bit differently (doesn't do useful locking :-) and seems to work with Roland patch. So I'm not going to touch it unless somebody reports me that it has problems

applied

Beware that the depend patch for __napi_synchronize() is still being discussed :-)

Cheers,
Ben.