Re: i40e: crash on NMI by continuous module reload

 

On February 27, 2015 2:42:29 PM EST, "Nelson, Shannon" [off-list ref] wrote:

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From: nick [mailto:xerofoify@gmail.com]
On 2015-02-27 09:16 AM, Stefan Assmann wrote:

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On 27.02.2015 15:02, nick wrote:

[...]

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    i40e: Fix a bug where Rx would stop after some time
[...]

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c

b/drivers/net/ethernet/intel/i40e/i40e_main.c

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index f7464e8..ff6d94d 100644

--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c

[...]

@@ -9169,6 +9178,13 @@ static int i40e_probe(struct pci_dev

*pdev,

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const struct pci_device_id *ent)

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 	if (err)
 		dev_info(&pf->pdev->dev, "set phy mask fail, aq_err %d\n",

err);

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+	msleep(75);
+	err = i40e_aq_set_link_restart_an(&pf->hw, true, NULL);
+	if (err) {
+		dev_info(&pf->pdev->dev, "link restart failed, aq_err=%d\n",
+			 pf->hw.aq.asq_last_status);
+	}
+
 	/* The main driver is (mostly) up and happy. We need to set

this

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state

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 	 * before setting up the misc vector or we get a race and the

vector

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 	 * ends up disabled forever.

With this hunk removed the driver successfully unloaded/reloaded

a

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couple of hundred times. Would it be safe to just remove this

hunk?

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I haven't seen any negative effects by removing this yet.

  Stefan

Stefan,
I wouldn't remove them yet as this does look like a valid idea to

check to see if the link is

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restarting successfully. On the other hand can you try removing

the

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msleep line as this one is

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most likely causing the issue due to sleeping for some long in a

probe function is generally a

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bad idea.
Thanks,
Nick

Thanks Nick for the quick reply. I tested removing the msleep but

that

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didn't make a difference. You actually need to remove the complete

hunk

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to get a stable driver reload.

  Stefan

Stefan,
Basically there are a few things that could be going wrong
1. You are getting a error return for the
function,i40e_aq_set_link_restart_an
2. You are trying to re able the device again when not needed
3. You are sending a NULL value to a field for command arguments that
takes a 0 and not NULL
to take no arguments
Nick

First of all, I would make sure you've got a short sleep in between
each load and unload in this stress test.  There's a lot going on under
the covers in the Firmware that really should be allowed to settle out
before jostling it again with another load/unload command.  

It would help to know what Firmware you have on your NIC - can you give
us the output from "ethtool -i <ethX>"?

The out-of-tree driver has just (finally!) been updated on SourceForge,
so you might give this version 1.2.37 driver a try to see if it changes
your result.  That code still has the hunk in question, but protected
by a FW version check.  The related patch will be headed upstream to
net-next very soon.

Firmware updates have also just been released, but I'm not sure they've
made it to the Intel Downloads site yet.  Updating your FW will make a
difference.

sln

Thanks Shannon, 
For the advice on there being a newer driver and firmware to test that on before reporting the bug against this driver. I am curious as to why this newer code is not up streamed to Linux next yet through. 
Nick
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.

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