Thread (5 messages) 5 messages, 2 authors, 2014-11-03
STALE4240d
Revisions (2)
  1. v1 current
  2. v2 [diff vs current]

[PATCH v1 2/2] drivers: net: xgene: fix: Use separate resources

From: Iyappan Subramanian <hidden>
Date: 2014-10-30 00:56:20
Also in: linux-arm-kernel, linux-devicetree
Subsystem: applied micro (apm) x-gene soc ethernet driver, networking drivers, the rest · Maintainers: Iyappan Subramanian, Keyur Chudgar, Quan Nguyen, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds

This patch fixes the following kernel crash during SGMII based 1GbE probe.

	BUG: Bad page state in process swapper/0  pfn:40fe6ad
	page:ffffffbee37a75d8 count:-1 mapcount:0 mapping:          (null) index:0x0
	flags: 0x0()
	page dumped because: nonzero _count
	Modules linked in:
	CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.17.0+ #7
	Call trace:
	[<ffffffc000087fa0>] dump_backtrace+0x0/0x12c
	[<ffffffc0000880dc>] show_stack+0x10/0x1c
	[<ffffffc0004d981c>] dump_stack+0x74/0xc4
	[<ffffffc00012fe70>] bad_page+0xd8/0x128
	[<ffffffc000133000>] get_page_from_freelist+0x4b8/0x640
	[<ffffffc000133260>] __alloc_pages_nodemask+0xd8/0x834
	[<ffffffc0004194f8>] __netdev_alloc_frag+0x124/0x1b8
	[<ffffffc00041bfdc>] __netdev_alloc_skb+0x90/0x10c
	[<ffffffc00039ff30>] xgene_enet_refill_bufpool+0x11c/0x280
	[<ffffffc0003a11a4>] xgene_enet_process_ring+0x168/0x340
	[<ffffffc0003a1498>] xgene_enet_napi+0x1c/0x50
	[<ffffffc00042b454>] net_rx_action+0xc8/0x18c
	[<ffffffc0000b0880>] __do_softirq+0x114/0x24c
	[<ffffffc0000b0c34>] irq_exit+0x94/0xc8
	[<ffffffc0000e68a0>] __handle_domain_irq+0x8c/0xf4
	[<ffffffc000081288>] gic_handle_irq+0x30/0x7c

This was due to hardware resource sharing conflict with the firmware. This
patch fixes this crash by using resources (descriptor ring, prefetch buffer)
that are not shared.

Signed-off-by: Iyappan Subramanian <redacted>
Signed-off-by: Keyur Chudgar <redacted>
---
 drivers/net/ethernet/apm/xgene/xgene_enet_main.c | 6 +++---
 drivers/net/ethernet/apm/xgene/xgene_enet_main.h | 3 +++
 2 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
index 3c208cc..ac37e26 100644
--- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
+++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c
@@ -639,9 +639,9 @@ static int xgene_enet_create_desc_rings(struct net_device *ndev)
 	struct device *dev = ndev_to_dev(ndev);
 	struct xgene_enet_desc_ring *rx_ring, *tx_ring, *cp_ring;
 	struct xgene_enet_desc_ring *buf_pool = NULL;
-	u8 cpu_bufnum = 0, eth_bufnum = 0;
-	u8 bp_bufnum = 0x20;
-	u16 ring_id, ring_num = 0;
+	u8 cpu_bufnum = 0, eth_bufnum = START_ETH_BUFNUM;
+	u8 bp_bufnum = START_BP_BUFNUM;
+	u16 ring_id, ring_num = START_RING_NUM;
 	int ret;
 
 	/* allocate rx descriptor ring */
diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.h b/drivers/net/ethernet/apm/xgene/xgene_enet_main.h
index 874e5a0..7d8b6ea 100644
--- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.h
+++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.h
@@ -38,6 +38,9 @@
 #define SKB_BUFFER_SIZE		(XGENE_ENET_MAX_MTU - NET_IP_ALIGN)
 #define NUM_PKT_BUF	64
 #define NUM_BUFPOOL	32
+#define START_ETH_BUFNUM	2
+#define START_BP_BUFNUM		0x22
+#define START_RING_NUM		8
 
 #define PHY_POLL_LINK_ON	(10 * HZ)
 #define PHY_POLL_LINK_OFF	(PHY_POLL_LINK_ON / 5)
-- 
1.9.1
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