From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ferruh Yigit <ferruh.yigit@intel.com>
Subject: Re: [PATCH] igb_uio: issue FLR during open and release
	of device file
Date: Thu, 6 Jul 2017 17:41:40 +0100
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 <1497260285-27536-1-git-send-email-shijith.thotton@caviumnetworks.com>
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Cc: Stephen Hemminger <stephen@networkplumber.org>,
 Qi Zhang <qi.z.zhang@intel.com>, Wenzhuo Lu <wenzhuo.lu@intel.com>,
 Thomas Monjalon <thomas@monjalon.net>, Jianfeng Tan
 <jianfeng.tan@intel.com>, Gregory Etelson <gregory@weka.io>
To: Shijith Thotton <shijith.thotton@caviumnetworks.com>, dev@dpdk.org
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On 6/12/2017 10:38 AM, Shijith Thotton wrote:
> Set UIO info device file operations open and release. Call pci reset
> function inside open and release to clear device state at start and end.
> Copied this behaviour from vfio_pci kernel module code. With this patch,
> it is not mandatory to issue FLR by PMD's during init and close.
> 
> Bus master enable and disable are added in open and release respectively
> to take care of device DMA.
> 
> Signed-off-by: Shijith Thotton <shijith.thotton@caviumnetworks.com>

This patch, and Gregory's patch [1] are very similar and main target is
to leave device in a more proper state when DPDK application quits
unexpectedly.

Difference between two are, this one implements both .open and .release
ops, and sets / clears bus master accordingly.

Although main concern is .reset, I am OK to follow vfio_pci approach
here, and clearing bus master on .reset can prevent unwanted DMA access.

So, I am for this patch and I am testing it for a few days without a
problem.

But Gregory reported a crash with older version of this patch, without
more detail, we should clear that first. With Gregory's Tested-by, I am
OK with this patch.


Gregory,

Are you using your version, what are the results? And would you mind
testing this patch?

Thanks,
ferruh


[1]
http://dpdk.org/dev/patchwork/patch/25061/