From: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
Russell Currey <ruscur@russell.cc>,
Oliver OHalloran <oohall@gmail.com>,
linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] PCI/AER: Handle Multi UnCorrectable/Correctable errors properly
Date: Wed, 11 May 2022 17:29:45 -0700 [thread overview]
Message-ID: <54ab824c-44a9-239a-9380-2f051f26a079@linux.intel.com> (raw)
In-Reply-To: <20220511234024.GA831116@bhelgaas>
On 5/11/22 4:40 PM, Bjorn Helgaas wrote:
> On Mon, Apr 18, 2022 at 03:02:37PM +0000, Kuppuswamy Sathyanarayanan wrote:
>> Currently the aer_irq() handler returns IRQ_NONE for cases without bits
>> PCI_ERR_ROOT_UNCOR_RCV or PCI_ERR_ROOT_COR_RCV are set. But this
>> assumption is incorrect.
>>
>> Consider a scenario where aer_irq() is triggered for a correctable
>> error, and while we process the error and before we clear the error
>> status in "Root Error Status" register, if the same kind of error
>> is triggered again, since aer_irq() only clears events it saw, the
>> multi-bit error is left in tact. This will cause the interrupt to fire
>> again, resulting in entering aer_irq() with just the multi-bit error
>> logged in the "Root Error Status" register.
>>
>> Repeated AER recovery test has revealed this condition does happen
>> and this prevents any new interrupt from being triggered. Allow to
>> process interrupt even if only multi-correctable (BIT 1) or
>> multi-uncorrectable bit (BIT 3) is set.
>>
>> Also note that, for cases with only multi-bit error is set, since this
>> is not the first occurrence of the error, PCI_ERR_ROOT_ERR_SRC may have
>> zero or some junk value. So we cannot cleanly process this error
>> information using aer_isr_one_error(). All we are attempting with this
>> fix is to make sure error interrupt processing can continue in this
>> scenario.
>>
>> This error can be reproduced by making following changes to the
>> aer_irq() function and by executing the given test commands.
>>
>> static irqreturn_t aer_irq(int irq, void *context)
>> struct aer_err_source e_src = {};
>>
>> pci_read_config_dword(rp, aer + PCI_ERR_ROOT_STATUS,
>> &e_src.status);
>> + pci_dbg(pdev->port, "Root Error Status: %04x\n",
>> + e_src.status);
>> if (!(e_src.status & AER_ERR_STATUS_MASK))
>
> Do you mean
>
> if (!(e_src.status & (PCI_ERR_ROOT_UNCOR_RCV|PCI_ERR_ROOT_COR_RCV)))
>
> here? AER_ERR_STATUS_MASK would be after this fix.
Yes. You are correct. Do you want me to update it and Fixes tag
and send next version?
>
>> return IRQ_NONE;
>>
>> + mdelay(5000);
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
next prev parent reply other threads:[~2022-05-12 0:29 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-18 15:02 [PATCH v3] PCI/AER: Handle Multi UnCorrectable/Correctable errors properly Kuppuswamy Sathyanarayanan
2022-05-11 15:19 ` Sathyanarayanan Kuppuswamy
2022-05-11 23:27 ` Bjorn Helgaas
2022-05-11 23:39 ` Sathyanarayanan Kuppuswamy
2022-05-11 23:40 ` Bjorn Helgaas
2022-05-12 0:29 ` Sathyanarayanan Kuppuswamy [this message]
2022-05-17 22:28 ` 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=54ab824c-44a9-239a-9380-2f051f26a079@linux.intel.com \
--to=sathyanarayanan.kuppuswamy@linux.intel.com \
--cc=bhelgaas@google.com \
--cc=helgaas@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=oohall@gmail.com \
--cc=ruscur@russell.cc \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).