From: "Sean V Kelley" <sean.v.kelley@intel.com>
To: "Bjorn Helgaas" <helgaas@kernel.org>
Cc: "Sean V Kelley" <seanvk.dev@oregontracks.org>,
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
Subject: Re: [PATCH v9 10/15] PCI/ERR: Limit AER resets in pcie_do_recovery()
Date: Fri, 16 Oct 2020 10:36:19 -0700 [thread overview]
Message-ID: <7E259265-CE19-450D-A902-6C531690939D@intel.com> (raw)
In-Reply-To: <20201016172210.GA86168@bjorn-Precision-5520>
On 16 Oct 2020, at 10:22, Bjorn Helgaas wrote:
> 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.
Agree, this is the patch that the check is needed as we are opening
things up for walking RC_ECs and RC_ENDs as below.
Sean
>
>> }
>>
>> 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
>>
next prev parent reply other threads:[~2020-10-16 17:36 UTC|newest]
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
2020-10-16 17:36 ` Sean V Kelley [this message]
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
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