From: "Alex G." <mr.nuke.me@gmail.com>
To: Ethan Zhao <haifeng.zhao@intel.com>,
bhelgaas@google.com, oohall@gmail.com, ruscur@russell.cc,
lukas@wunner.de, andriy.shevchenko@linux.intel.com,
stuart.w.hayes@gmail.com, mika.westerberg@linux.intel.com
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
pei.p.jia@intel.com
Subject: Re: [PATCH 4/5] PCI: only return true when dev io state is really changed
Date: Fri, 25 Sep 2020 08:56:30 -0500 [thread overview]
Message-ID: <718244ed-9069-6ef9-9144-e7b80c03a6c6@gmail.com> (raw)
In-Reply-To: <20200925023423.42675-5-haifeng.zhao@intel.com>
Hi Ethan,
On 9/24/20 9:34 PM, Ethan Zhao wrote:
> When uncorrectable error happens, AER driver and DPC driver interrupt
> handlers likely call
> pcie_do_recovery()->pci_walk_bus()->report_frozen_detected() with
> pci_channel_io_frozen the same time.
> If pci_dev_set_io_state() return true even if the original state is
> pci_channel_io_frozen, that will cause AER or DPC handler re-enter
> the error detecting and recovery procedure one after another.
> The result is the recovery flow mixed between AER and DPC.
> So simplify the pci_dev_set_io_state() function to only return true
> when dev->error_state is changed.
>
> Signed-off-by: Ethan Zhao <haifeng.zhao@intel.com>
> Tested-by: Wen jin <wen.jin@intel.com>
> Tested-by: Shanshan Zhang <ShanshanX.Zhang@intel.com>
> ---
> drivers/pci/pci.h | 31 +++----------------------------
> 1 file changed, 3 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index fa12f7cbc1a0..d420bb977f3b 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -362,35 +362,10 @@ static inline bool pci_dev_set_io_state(struct pci_dev *dev,
> bool changed = false;
>
> device_lock_assert(&dev->dev);
> - switch (new) {
> - case pci_channel_io_perm_failure:
> - switch (dev->error_state) {
> - case pci_channel_io_frozen:
> - case pci_channel_io_normal:
> - case pci_channel_io_perm_failure:
> - changed = true;
> - break;
> - }
> - break;
> - case pci_channel_io_frozen:
> - switch (dev->error_state) {
> - case pci_channel_io_frozen:
> - case pci_channel_io_normal:
> - changed = true;
> - break;
> - }
> - break;
> - case pci_channel_io_normal:
> - switch (dev->error_state) {
> - case pci_channel_io_frozen:
> - case pci_channel_io_normal:
> - changed = true;
> - break;
> - }
> - break;
> - }
> - if (changed)
> + if (dev->error_state != new) {
> dev->error_state = new;
> + changed = true;
> + }
> return changed;
> }
The flow is a lot easier to follow now. Thank you.
Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
next prev parent reply other threads:[~2020-09-25 13:56 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-25 2:34 [PATCH 0/5] Fix DPC hotplug race and enhance error hanlding Ethan Zhao
2020-09-25 2:34 ` [PATCH 4/5] PCI: only return true when dev io state is really changed Ethan Zhao
2020-09-25 12:38 ` Andy Shevchenko
2020-09-27 1:28 ` Zhao, Haifeng
2020-09-25 13:56 ` Alex G. [this message]
2020-09-25 2:34 ` [PATCH 5/5] PCI/ERR: don't mix io state not changed and no driver together Ethan Zhao
[not found] ` <20200925023423.42675-2-haifeng.zhao@intel.com>
2020-09-25 12:24 ` [PATCH 1/5] PCI: define a function to check and wait till port finish DPC handling Andy Shevchenko
2020-09-27 1:53 ` Zhao, Haifeng
[not found] ` <20200925023423.42675-3-haifeng.zhao@intel.com>
2020-09-25 12:32 ` [PATCH 2/5] PCI: pciehp: check and wait port status out of DPC before handling DLLSC and PDC Andy Shevchenko
2020-09-27 1:50 ` Zhao, Haifeng
[not found] ` <20200925023423.42675-4-haifeng.zhao@intel.com>
2020-09-25 12:35 ` [PATCH 3/5] PCI/ERR: get device before call device driver to avoid null pointer reference Andy Shevchenko
2020-09-29 2:35 ` Ethan Zhao
2020-09-29 8:51 ` Andy Shevchenko
2020-09-29 9:38 ` Ethan Zhao
2020-09-29 10:48 ` Andy Shevchenko
2020-09-30 2:07 ` Ethan Zhao
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