Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <6e7fe17a30e455187066da1079fad0941f5aa5cc.camel@perches.com>
Subject: Re: [PATCH 4/5 V4] PCI: only return true when dev io state is
 really changed
From:   Joe Perches <joe@perches.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,
        mr.nuke.me@gmail.com, mika.westerberg@linux.intel.com
Cc:     linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        pei.p.jia@intel.com, ashok.raj@linux.intel.com,
        sathyanarayanan.kuppuswamy@intel.com, hch@infradead.org
Date:   Sun, 27 Sep 2020 02:14:25 -0700
In-Reply-To: <20200927082736.14633-5-haifeng.zhao@intel.com>
References: <20200927082736.14633-1-haifeng.zhao@intel.com>
         <20200927082736.14633-5-haifeng.zhao@intel.com>
Content-Type: text/plain; charset="ISO-8859-1"
User-Agent: Evolution 3.36.4-0ubuntu1 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Sun, 2020-09-27 at 04:27 -0400, 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>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Reviewed-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
> Reviewed-by: Joe Perches <joe@perches.com>

Hi Ethan/Haifeng.

Like Andy, I did not "review" this patch and sign it.
I merely suggested another simplification.
Please do not add -by: lines unless actually received by you.