[e1000 netdev-2.6 4/6] 82547 interrupt assert/de-assert re-ordering
From: Feldman, Scott <hidden>
Date: 2004-02-02 22:01:49
* 82547 needs interrupt disable/enable to keep interrupt assertion state synced between 82547 and APIC. 82547 will re-order assert and de-assert messages if hub link bus is busy (heavy traffic). Disabling interrupt on device works around re- order issue. Note: this is a re-patch. We backed out the patch because of a report on a system with a 8086:1019 device would lock up with this patch. Turns out that system was a pre-production sample. ----------- diff -Naurp netdev-2.6/drivers/net/e1000/e1000_main.c netdev-2.6/drivers/net/e1000.mod/e1000_main.c
--- netdev-2.6/drivers/net/e1000/e1000_main.c 2004-02-02 12:09:08.000000000 -0800
+++ netdev-2.6/drivers/net/e1000.mod/e1000_main.c 2004-02-02 12:10:43.000000000 -0800@@ -2119,10 +2119,26 @@ e1000_intr(int irq, void *data, struct p __netif_rx_schedule(netdev); } #else + /* Writing IMC and IMS is needed for 82547. + Due to Hub Link bus being occupied, an interrupt + de-assertion message is not able to be sent. + When an interrupt assertion message is generated later, + two messages are re-ordered and sent out. + That causes APIC to think 82547 is in de-assertion + state, while 82547 is in assertion state, resulting + in dead lock. Writing IMC forces 82547 into + de-assertion state. + */ + if(hw->mac_type == e1000_82547 || hw->mac_type == e1000_82547_rev_2) + e1000_irq_disable(adapter); + for(i = 0; i < E1000_MAX_INTR; i++) if(!e1000_clean_rx_irq(adapter) & !e1000_clean_tx_irq(adapter)) break; + + if(hw->mac_type == e1000_82547 || hw->mac_type == e1000_82547_rev_2) + e1000_irq_enable(adapter); #endif return IRQ_HANDLED;