Patchwork net/tg3: Avoid delay during MMIO access

login
register
mail settings
Submitter Gavin Shan
Date June 25, 2013, 7:24 a.m.
Message ID <1372145072-8559-1-git-send-email-shangw@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/254045/
State Accepted
Delegated to: David Miller
Headers show

Comments

Gavin Shan - June 25, 2013, 7:24 a.m.
When the EEH error is the result of a fenced host bridge, MMIO accesses
can be very slow (milliseconds) to timeout and return all 1's,
thus causing the driver various timeout loops to take way too long and
trigger soft-lockup warnings (in addition to taking minutes to recover).

It might be worthwhile to check if for any of these cases, ffffffff is
a valid possible value, and if not, bail early since that means the HW
is either gone or isolated. In the meantime, checking that the PCI channel
is offline would be workaround of the problem.

Cc: <stable@vger.kernel.org> # v3.0+
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
---
 drivers/net/ethernet/broadcom/tg3.c |   36 +++++++++++++++++++++++++++++++++++
 1 files changed, 36 insertions(+), 0 deletions(-)
David Miller - June 26, 2013, 12:01 a.m.
From: Gavin Shan <shangw@linux.vnet.ibm.com>
Date: Tue, 25 Jun 2013 15:24:32 +0800

> When the EEH error is the result of a fenced host bridge, MMIO accesses
> can be very slow (milliseconds) to timeout and return all 1's,
> thus causing the driver various timeout loops to take way too long and
> trigger soft-lockup warnings (in addition to taking minutes to recover).
> 
> It might be worthwhile to check if for any of these cases, ffffffff is
> a valid possible value, and if not, bail early since that means the HW
> is either gone or isolated. In the meantime, checking that the PCI channel
> is offline would be workaround of the problem.
> 
> Cc: <stable@vger.kernel.org> # v3.0+
> Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>

Applied and queued up for -stable, thanks.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index c777b90..a13463e 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -744,6 +744,9 @@  static int tg3_ape_lock(struct tg3 *tp, int locknum)
 		status = tg3_ape_read32(tp, gnt + off);
 		if (status == bit)
 			break;
+		if (pci_channel_offline(tp->pdev))
+			break;
+
 		udelay(10);
 	}
 
@@ -1635,6 +1638,9 @@  static void tg3_wait_for_event_ack(struct tg3 *tp)
 	for (i = 0; i < delay_cnt; i++) {
 		if (!(tr32(GRC_RX_CPU_EVENT) & GRC_RX_CPU_DRIVER_EVENT))
 			break;
+		if (pci_channel_offline(tp->pdev))
+			break;
+
 		udelay(8);
 	}
 }
@@ -1813,6 +1819,9 @@  static int tg3_poll_fw(struct tg3 *tp)
 		for (i = 0; i < 200; i++) {
 			if (tr32(VCPU_STATUS) & VCPU_STATUS_INIT_DONE)
 				return 0;
+			if (pci_channel_offline(tp->pdev))
+				return -ENODEV;
+
 			udelay(100);
 		}
 		return -ENODEV;
@@ -1823,6 +1832,15 @@  static int tg3_poll_fw(struct tg3 *tp)
 		tg3_read_mem(tp, NIC_SRAM_FIRMWARE_MBOX, &val);
 		if (val == ~NIC_SRAM_FIRMWARE_MBOX_MAGIC1)
 			break;
+		if (pci_channel_offline(tp->pdev)) {
+			if (!tg3_flag(tp, NO_FWARE_REPORTED)) {
+				tg3_flag_set(tp, NO_FWARE_REPORTED);
+				netdev_info(tp->dev, "No firmware running\n");
+			}
+
+			break;
+		}
+
 		udelay(10);
 	}
 
@@ -3520,6 +3538,8 @@  static int tg3_pause_cpu(struct tg3 *tp, u32 cpu_base)
 		tw32(cpu_base + CPU_MODE,  CPU_MODE_HALT);
 		if (tr32(cpu_base + CPU_MODE) & CPU_MODE_HALT)
 			break;
+		if (pci_channel_offline(tp->pdev))
+			return -EBUSY;
 	}
 
 	return (i == iters) ? -EBUSY : 0;
@@ -8589,6 +8609,14 @@  static int tg3_stop_block(struct tg3 *tp, unsigned long ofs, u32 enable_bit, boo
 	tw32_f(ofs, val);
 
 	for (i = 0; i < MAX_WAIT_CNT; i++) {
+		if (pci_channel_offline(tp->pdev)) {
+			dev_err(&tp->pdev->dev,
+				"tg3_stop_block device offline, "
+				"ofs=%lx enable_bit=%x\n",
+				ofs, enable_bit);
+			return -ENODEV;
+		}
+
 		udelay(100);
 		val = tr32(ofs);
 		if ((val & enable_bit) == 0)
@@ -8612,6 +8640,13 @@  static int tg3_abort_hw(struct tg3 *tp, bool silent)
 
 	tg3_disable_ints(tp);
 
+	if (pci_channel_offline(tp->pdev)) {
+		tp->rx_mode &= ~(RX_MODE_ENABLE | TX_MODE_ENABLE);
+		tp->mac_mode &= ~MAC_MODE_TDE_ENABLE;
+		err = -ENODEV;
+		goto err_no_dev;
+	}
+
 	tp->rx_mode &= ~RX_MODE_ENABLE;
 	tw32_f(MAC_RX_MODE, tp->rx_mode);
 	udelay(10);
@@ -8660,6 +8695,7 @@  static int tg3_abort_hw(struct tg3 *tp, bool silent)
 	err |= tg3_stop_block(tp, BUFMGR_MODE, BUFMGR_MODE_ENABLE, silent);
 	err |= tg3_stop_block(tp, MEMARB_MODE, MEMARB_MODE_ENABLE, silent);
 
+err_no_dev:
 	for (i = 0; i < tp->irq_cnt; i++) {
 		struct tg3_napi *tnapi = &tp->napi[i];
 		if (tnapi->hw_status)