Re: [PATCH v7 05/13] PCI/ERR: Use "bridge" for clarity in pcie_do_recovery()

[Sean V Kelley]

On 1 Oct 2020, at 2:06, Jonathan Cameron wrote:

> On Wed, 30 Sep 2020 14:58:12 -0700
> Sean V Kelley <seanvk.dev@xxxxxxxxxxxxxxxx> wrote:
>
> > From: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
> >
> > The term "dev" is being applied to root ports, switch
> > upstream ports, switch downstream ports, and the upstream
> > ports on endpoints. While endpoint upstream ports don't have
> > subordinate buses, a generic term such as "bridge" may be used
>
> This sentence is a bit confusing.  The bit before the comma
> seems only slightly connected. Perhaps 2 sentences?

I agree.  Will reword.
> > for something with a subordinate bus. The current conditional
> > logic in pcie_do_recovery() would also benefit from some
> > simplification with use of pci_upstream_bridge() in place of
> > dev->bus->self. Reverse the pcie_do_recovery() conditional logic
> > and replace use of "dev" with "bridge" for greater clarity.
> >
> > Suggested-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> > Signed-off-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
>
> Acked-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

Thanks,

Sean

> > ---
> >  drivers/pci/pcie/err.c | 20 +++++++++++++-------
> >  1 file changed, 13 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
> > index 950612342f1c..c6922c099c76 100644
> > --- a/drivers/pci/pcie/err.c
> > +++ b/drivers/pci/pcie/err.c
> > @@ -152,16 +152,22 @@ pci_ers_result_t pcie_do_recovery(struct 
> > pci_dev *dev,
> >  {
> >  	pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
> >  	struct pci_bus *bus;
> > +	struct pci_dev *bridge;
> > +	int type;
> >
> >  	/*
> > -	 * Error recovery runs on all subordinates of the first downstream 
> > port.
> > -	 * If the downstream port detected the error, it is cleared at the 
> > end.
> > +	 * Error recovery runs on all subordinates of the first downstream
> > +	 * bridge. If the downstream bridge detected the error, it is
> > +	 * cleared at the end.
> >  	 */
> > -	if (!(pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
> > -	      pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM))
> > -		dev = dev->bus->self;
> > -	bus = dev->subordinate;
> > -
> > +	type = pci_pcie_type(dev);
> > +	if (type == PCI_EXP_TYPE_ROOT_PORT ||
> > +	    type == PCI_EXP_TYPE_DOWNSTREAM)
> > +		bridge = dev;
> > +	else
> > +		bridge = pci_upstream_bridge(dev);
> > +
> > +	bus = bridge->subordinate;
> >  	pci_dbg(dev, "broadcast error_detected message\n");
> >  	if (state == pci_channel_io_frozen) {
> >  		pci_walk_bus(bus, report_frozen_detected, &status);