Linux-PCI Archive on lore.kernel.org
 help / color / Atom feed
From: Bjorn Helgaas <helgaas@kernel.org>
To: Sean V Kelley <seanvk.dev@oregontracks.org>
Cc: bhelgaas@google.com, Jonathan.Cameron@huawei.com,
	rafael.j.wysocki@intel.com, ashok.raj@intel.com,
	tony.luck@intel.com, sathyanarayanan.kuppuswamy@intel.com,
	qiuxu.zhuo@intel.com, linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Sean V Kelley <sean.v.kelley@intel.com>
Subject: Re: [PATCH v9 10/15] PCI/ERR: Limit AER resets in pcie_do_recovery()
Date: Fri, 16 Oct 2020 12:22:10 -0500
Message-ID: <20201016172210.GA86168@bjorn-Precision-5520> (raw)
In-Reply-To: <20201016001113.2301761-11-seanvk.dev@oregontracks.org>

On Thu, Oct 15, 2020 at 05:11:08PM -0700, Sean V Kelley wrote:
> From: Sean V Kelley <sean.v.kelley@intel.com>
> 
> In some cases a bridge may not exist as the hardware controlling may be
> handled only by firmware and so is not visible to the OS. This scenario is
> also possible in future use cases involving non-native use of RCECs by
> firmware.
> 
> Explicitly apply conditional logic around these resets by limiting them to
> Root Ports and Downstream Ports.
> 
> Link: https://lore.kernel.org/r/20201002184735.1229220-8-seanvk.dev@oregontracks.org
> Signed-off-by: Sean V Kelley <sean.v.kelley@intel.com>
> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---
>  drivers/pci/pcie/err.c | 31 +++++++++++++++++++++++++------
>  1 file changed, 25 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
> index 8b53aecdb43d..7883c9791562 100644
> --- a/drivers/pci/pcie/err.c
> +++ b/drivers/pci/pcie/err.c
> @@ -148,13 +148,17 @@ static int report_resume(struct pci_dev *dev, void *data)
>  
>  /**
>   * pci_walk_bridge - walk bridges potentially AER affected
> - * @bridge:	bridge which may be a Port
> + * @bridge:	bridge which may be a Port, an RCEC with associated RCiEPs,
> + *		or an RCiEP associated with an RCEC
>   * @cb:		callback to be called for each device found
>   * @userdata:	arbitrary pointer to be passed to callback
>   *
>   * If the device provided is a bridge, walk the subordinate bus, including
>   * any bridged devices on buses under this bus.  Call the provided callback
>   * on each device found.
> + *
> + * If the device provided has no subordinate bus, call the callback on the
> + * device itself.
>   */
>  static void pci_walk_bridge(struct pci_dev *bridge,
>  			    int (*cb)(struct pci_dev *, void *),
> @@ -162,6 +166,8 @@ static void pci_walk_bridge(struct pci_dev *bridge,
>  {
>  	if (bridge->subordinate)
>  		pci_walk_bus(bridge->subordinate, cb, userdata);
> +	else
> +		cb(bridge, userdata);

Looks like *this* is the patch where the "no subordinate bus" case
becomes possible?  If you agree, I can just move the test here, no
need to repost.

>  }
>  
>  pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
> @@ -174,10 +180,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
>  
>  	/*
>  	 * Error recovery runs on all subordinates of the bridge.  If the
> -	 * bridge detected the error, it is cleared at the end.
> +	 * bridge detected the error, it is cleared at the end.  For RCiEPs
> +	 * we should reset just the RCiEP itself.
>  	 */
>  	if (type == PCI_EXP_TYPE_ROOT_PORT ||
> -	    type == PCI_EXP_TYPE_DOWNSTREAM)
> +	    type == PCI_EXP_TYPE_DOWNSTREAM ||
> +	    type == PCI_EXP_TYPE_RC_EC ||
> +	    type == PCI_EXP_TYPE_RC_END)
>  		bridge = dev;
>  	else
>  		bridge = pci_upstream_bridge(dev);
> @@ -185,6 +194,12 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
>  	pci_dbg(bridge, "broadcast error_detected message\n");
>  	if (state == pci_channel_io_frozen) {
>  		pci_walk_bridge(bridge, report_frozen_detected, &status);
> +		if (type == PCI_EXP_TYPE_RC_END) {
> +			pci_warn(dev, "subordinate device reset not possible for RCiEP\n");
> +			status = PCI_ERS_RESULT_NONE;
> +			goto failed;
> +		}
> +
>  		status = reset_subordinates(bridge);
>  		if (status != PCI_ERS_RESULT_RECOVERED) {
>  			pci_warn(bridge, "subordinate device reset failed\n");
> @@ -217,9 +232,13 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
>  	pci_dbg(bridge, "broadcast resume message\n");
>  	pci_walk_bridge(bridge, report_resume, &status);
>  
> -	if (pcie_aer_is_native(bridge))
> -		pcie_clear_device_status(bridge);
> -	pci_aer_clear_nonfatal_status(bridge);
> +	if (type == PCI_EXP_TYPE_ROOT_PORT ||
> +	    type == PCI_EXP_TYPE_DOWNSTREAM ||
> +	    type == PCI_EXP_TYPE_RC_EC) {
> +		if (pcie_aer_is_native(bridge))
> +			pcie_clear_device_status(bridge);
> +		pci_aer_clear_nonfatal_status(bridge);
> +	}
>  	pci_info(bridge, "device recovery successful\n");
>  	return status;
>  
> -- 
> 2.28.0
> 

  reply index

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-16  0:10 [PATCH v9 00/15] Add RCEC handling to PCI/AER Sean V Kelley
2020-10-16  0:10 ` [PATCH v9 01/15] PCI/RCEC: Add RCEC class code and extended capability Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 02/15] PCI/RCEC: Bind RCEC devices to the Root Port driver Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 03/15] PCI/RCEC: Cache RCEC capabilities in pci_init_capabilities() Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 04/15] PCI/ERR: Rename reset_link() to reset_subordinates() Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 05/15] PCI/ERR: Simplify by using pci_upstream_bridge() Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 06/15] PCI/ERR: Simplify by computing pci_pcie_type() once Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 07/15] PCI/ERR: Use "bridge" for clarity in pcie_do_recovery() Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 08/15] PCI/ERR: Avoid negated conditional for clarity Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 09/15] PCI/ERR: Add pci_walk_bridge() to pcie_do_recovery() Sean V Kelley
2020-10-16 17:19   ` Bjorn Helgaas
2020-10-16  0:11 ` [PATCH v9 10/15] PCI/ERR: Limit AER resets in pcie_do_recovery() Sean V Kelley
2020-10-16 17:22   ` Bjorn Helgaas [this message]
2020-10-16 17:36     ` Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 11/15] PCI/RCEC: Add pcie_link_rcec() to associate RCiEPs Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 12/15] PCI/RCEC: Add RCiEP's linked RCEC to AER/ERR Sean V Kelley
2020-10-16 20:30   ` Bjorn Helgaas
2020-10-16 22:29     ` Bjorn Helgaas
2020-10-17  0:28       ` Kuppuswamy, Sathyanarayanan
2020-10-17  1:45       ` Kuppuswamy, Sathyanarayanan
2020-10-19 10:49       ` Ethan Zhao
2020-10-19 18:31         ` Sean V Kelley
2020-10-19 18:59           ` Kuppuswamy, Sathyanarayanan
2020-10-19 20:50             ` Sean V Kelley
2020-10-20 12:59               ` Jonathan Cameron
2020-10-20 16:28                 ` Bjorn Helgaas
2020-10-17 16:14     ` Sean V Kelley
2020-10-19 19:07       ` Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 13/15] PCI/AER: Add pcie_walk_rcec() to RCEC AER handling Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 14/15] PCI/PME: Add pcie_walk_rcec() to RCEC PME handling Sean V Kelley
2020-10-16  0:11 ` [PATCH v9 15/15] PCI/AER: Add RCEC AER error injection support Sean V Kelley

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=20201016172210.GA86168@bjorn-Precision-5520 \
    --to=helgaas@kernel.org \
    --cc=Jonathan.Cameron@huawei.com \
    --cc=ashok.raj@intel.com \
    --cc=bhelgaas@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=qiuxu.zhuo@intel.com \
    --cc=rafael.j.wysocki@intel.com \
    --cc=sathyanarayanan.kuppuswamy@intel.com \
    --cc=sean.v.kelley@intel.com \
    --cc=seanvk.dev@oregontracks.org \
    --cc=tony.luck@intel.com \
    /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