Linux-PCI Archive on lore.kernel.org
 help / color / Atom feed
From: "Kuppuswamy, Sathyanarayanan"  <sathyanarayanan.kuppuswamy@linux.intel.com>
To: Sinan Kaya <okaya@kernel.org>, Bjorn Helgaas <helgaas@kernel.org>
Cc: bhelgaas@google.com, linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org, ashok.raj@intel.com,
	Jay Vosburgh <jay.vosburgh@canonical.com>
Subject: Re: [PATCH v3 1/1] PCI/ERR: Fix reset logic in pcie_do_recovery() call
Date: Fri, 25 Sep 2020 10:11:32 -0700
Message-ID: <4ae86061-2182-bcf1-ebd7-485acf2d47b9@linux.intel.com> (raw)
In-Reply-To: <65238d0b-0a39-400a-3a18-4f68eb554538@kernel.org>



On 9/25/20 9:55 AM, Sinan Kaya wrote:
> On 9/25/2020 1:11 AM, Kuppuswamy, Sathyanarayanan wrote:
>>
>>
>> On 9/24/20 1:52 PM, Sinan Kaya wrote:
>>> On 9/24/2020 12:06 AM, Kuppuswamy, Sathyanarayanan wrote:
> 
>>>
>>> So, this is a matter of moving the save/restore logic from the hotplug
>>> driver into common code so that DPC slot reset takes advantage of it?
>> We are not moving it out of hotplug path. But fixing it in this code path.
>> With this fix, we will not depend on hotplug driver to restore the state.
> 
> Any possibility of unification?
If we do that, it might need rework of hotplug driver. It will be a big
change. IMO, its better not to touch that bee hive.
> 
> 
> [snip]
>>>
>>>> To fix above issues, use PCI_ERS_RESULT_NEED_RESET as error state after
>>>> successful reset_link() operation. This will ensure ->slot_reset() be
>>>> called after reset_link() operation for fatal errors.
>>>
>>> You lost me here. Why do we want to do secondary bus reset on top of
>>> DPC reset?
>> For non-hotplug capable slots, when reset (PCI_ERS_RESULT_NEED_RESET) is
>> requested, we want to reset it before calling ->slot_reset() callback.
> 
> Why? Isn't DPC slot reset enough?
It will do the reset at hardware level. But driver state is not
cleaned up. So doing bus reset will restore both driver and
hardware states.
Also for non-fatal errors, if reset is requested then we still need
some kind of bus reset call here.
> What will bus reset do that DPC slot reset won't do?
> 
> I can understand calling bus reset if DPC is not supported.
> I don't understand the requirement to do double reset.
> 

-- 
Sathyanarayanan Kuppuswamy
Linux Kernel Developer

  reply index

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <3cad1a07-509b-ef51-f635-71def2ff8293@linux.intel.com>
2020-09-22 23:33 ` Bjorn Helgaas
2020-09-22 23:44   ` Kuppuswamy, Sathyanarayanan
2020-09-24  1:15     ` Sinan Kaya
2020-09-24  2:04       ` Kuppuswamy, Sathyanarayanan
2020-09-24  2:16         ` Sinan Kaya
2020-09-24  2:51           ` Kuppuswamy, Sathyanarayanan
2020-09-24  3:13             ` Sinan Kaya
2020-09-24  4:06               ` Kuppuswamy, Sathyanarayanan
2020-09-24 20:52                 ` Sinan Kaya
2020-09-25  5:11                   ` Kuppuswamy, Sathyanarayanan
2020-09-25 16:55                     ` Sinan Kaya
2020-09-25 17:11                       ` Kuppuswamy, Sathyanarayanan [this message]
2020-09-25 17:47                         ` Sinan Kaya
2020-09-25 18:16                           ` Kuppuswamy, Sathyanarayanan
2020-09-25 18:30                             ` Sinan Kaya
2020-09-28  2:43                               ` Kuppuswamy, Sathyanarayanan
2020-09-28  8:41                                 ` Ethan Zhao
2020-09-28 11:17                                 ` Sinan Kaya
2020-09-28 12:16                                   ` Sinan Kaya
2020-09-28 17:15                                   ` Kuppuswamy, Sathyanarayanan
2020-09-28 18:02                                     ` Sinan Kaya
2020-09-28 18:25                                       ` Sinan Kaya
2020-09-28 18:32                                         ` Kuppuswamy, Sathyanarayanan
2020-10-12  5:13                                           ` Kuppuswamy, Sathyanarayanan
2020-10-12 14:51                                             ` Sinan Kaya
2020-09-28 12:11                                 ` Sinan Kaya
2020-09-25 23:50                             ` Sinan Kaya
2020-07-24 19:07 sathyanarayanan.kuppuswamy
2020-09-01  5:41 ` Kuppuswamy, Sathyanarayanan
2020-09-22 18:52 ` Bjorn Helgaas

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4ae86061-2182-bcf1-ebd7-485acf2d47b9@linux.intel.com \
    --to=sathyanarayanan.kuppuswamy@linux.intel.com \
    --cc=ashok.raj@intel.com \
    --cc=bhelgaas@google.com \
    --cc=helgaas@kernel.org \
    --cc=jay.vosburgh@canonical.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=okaya@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-PCI Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-pci/0 linux-pci/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-pci linux-pci/ https://lore.kernel.org/linux-pci \
		linux-pci@vger.kernel.org
	public-inbox-index linux-pci

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-pci


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git