linux-kernel - Re: [PATCH v9 5/8] PCI/AER: Allow clearing Error Status Register in FF mode

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Message-ID: <20191029230346.GA123765@google.com>
Date:   Tue, 29 Oct 2019 18:03:46 -0500
From:   Bjorn Helgaas <helgaas@...nel.org>
To:     Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@...ux.intel.com>
Cc:     linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
        ashok.raj@...el.com, keith.busch@...el.com
Subject: Re: [PATCH v9 5/8] PCI/AER: Allow clearing Error Status Register in
 FF mode

On Tue, Oct 29, 2019 at 12:58:14PM -0700, Kuppuswamy Sathyanarayanan wrote:
> 
> On 10/28/19 4:22 PM, Bjorn Helgaas wrote:
> > On Thu, Oct 03, 2019 at 04:39:01PM -0700, sathyanarayanan.kuppuswamy@...ux.intel.com wrote:
> > > From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>

> > > @@ -430,9 +424,6 @@ int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
> > >   	if (!pos)
> > >   		return -EIO;
> > > -	if (pcie_aer_get_firmware_first(dev))
> > > -		return -EIO;
> > > -
> > >   	port_type = pci_pcie_type(dev);
> > >   	if (port_type == PCI_EXP_TYPE_ROOT_PORT) {
> > >   		pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status);
> > > @@ -455,7 +446,8 @@ void pci_aer_init(struct pci_dev *dev)
> > >   	if (dev->aer_cap)
> > >   		dev->aer_stats = kzalloc(sizeof(struct aer_stats), GFP_KERNEL);
> > > -	pci_cleanup_aer_error_status_regs(dev);
> > > +	if (!pcie_aer_get_firmware_first(dev))
> > > +		pci_cleanup_aer_error_status_regs(dev);
> >
> > This effectively moves the "if (pcie_aer_get_firmware_first())" check
> > from pci_cleanup_aer_error_status_regs() into one of the callers.  But
> > there are two other callers: pci_aer_init() and pci_restore_state().
> > Do they need the change, or do you want to cleanup the AER error
> > registers there, but not here?
>
> Good catch. I have added this check to pci_aer_init(). But it needs
> to be added to pci_restore_state() as well. Instead of moving the
> checks to the caller, If you agree, I could change the API to
> pci_cleanup_aer_error_status_regs(struct pci_dev *dev, bool
> skip_ff_check) and let the caller decide whether they want skip the
> check or not.

If all callers of pci_cleanup_aer_error_status_regs() would have to
check pcie_aer_get_firmware_first(), I don't understand why you're
moving the check at all.