Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 28 Jun 2023 15:29:44 +0200
From:   Lukas Wunner <lukas@wunner.de>
To:     Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>
Cc:     Sathyanarayanan Kuppuswamy 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        Bjorn Helgaas <bhelgaas@google.com>, oohall@gmail.com,
        Mahesh J Salgaonkar <mahesh@linux.ibm.com>,
        Yazen Ghannam <yazen.ghannam@amd.com>,
        Fontenot Nathan <Nathan.Fontenot@amd.com>
Subject: Re: [PATCH v3 1/2] PCI: pciehp: Add support for async hotplug with
 native AER and DPC/EDR
Message-ID: <20230628132944.GB14276@wunner.de>
References: <20230621185152.105320-1-Smita.KoralahalliChannabasappa@amd.com>
 <20230621185152.105320-2-Smita.KoralahalliChannabasappa@amd.com>
 <e7aa803b-2b43-dc43-1d92-38bcca636e62@linux.intel.com>
 <a79c82bb-e1fe-891c-87f9-6231a30e5ef2@amd.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <a79c82bb-e1fe-891c-87f9-6231a30e5ef2@amd.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Precedence: bulk

On Tue, Jun 27, 2023 at 10:48:37AM -0700, Smita Koralahalli wrote:
> On 6/22/2023 4:22 PM, Sathyanarayanan Kuppuswamy wrote:
> > On 6/21/23 11:51 AM, Smita Koralahalli wrote:
> > > +static void dpc_handle_surprise_removal(struct pci_dev *pdev)
> > > +{
> > > +	if (pdev->dpc_rp_extensions && dpc_wait_rp_inactive(pdev)) {
> > > +		pci_err(pdev, "failed to retrieve DPC root port on async remove\n");
> > > +		goto out;
> > > +	}
> > > +
> > > +	pci_aer_raw_clear_status(pdev);
> > > +	pci_clear_surpdn_errors(pdev);
> > > +
> > > +	pci_write_config_word(pdev, pdev->dpc_cap + PCI_EXP_DPC_STATUS,
> > > +			      PCI_EXP_DPC_STATUS_TRIGGER);
> > 
> > Don't you need to wait for the link to go down?
> 
> Yes will include, pcie_wait_for_link()..
> 
> Should this check be here or at the beginning of the function before we
> check pdev->dpc_rp_extensions?

I'd just use the same order as dpc_reset_link(), i.e. checking for
!pcie_wait_for_link() happens before the check for pdev->dpc_rp_extensions.

Thanks,

Lukas