RE: [PATCH v6 06/10] PCI: dwc: Add reset_all_bars flag

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Hi Lorenzo,

> From: Lorenzo Pieralisi, Sent: Friday, November 11, 2022 9:34 PM
> 
> On Thu, Sep 22, 2022 at 05:06:43PM +0900, Yoshihiro Shimoda wrote:
> > Some PCIe endpoint drivers reset all BARs in each ep_init() ops.
> > So, we can reset the BARs into the common code if the flag is set.
> 
> Is there a reason why only some drivers do it ? What I am really asking
> is whether instead of a flag we could reset them unconditionally in all
> drivers.
> 
> It would be good to come up with a set of guidelines on kernel
> expectations rather than adding them per EP.

Thank you very much for your comments! I realized that this is
completely unnecessary code because a PCIe endpoint function driver
will call pci_epc_set_bar() to prepare BAR(s). So, I'll drop this patch
on v7.

Best regards,
Yoshihiro Shimoda

> Lorenzo
> 
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > ---
> >  drivers/pci/controller/dwc/pcie-designware-ep.c | 10 ++++++++++
> >  drivers/pci/controller/dwc/pcie-designware.h    |  1 +
> >  2 files changed, 11 insertions(+)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > index 1b7e9e1b8d52..a79482824e74 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > @@ -83,6 +83,14 @@ void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
> >  }
> >  EXPORT_SYMBOL_GPL(dw_pcie_ep_reset_bar);
> >
> > +static void dw_pcie_ep_reset_all_bars(struct dw_pcie *pci)
> > +{
> > +	enum pci_barno bar;
> > +
> > +	for (bar = BAR_0; bar < PCI_STD_NUM_BARS; bar++)
> > +		dw_pcie_ep_reset_bar(pci, bar);
> > +}
> > +
> >  static u8 __dw_pcie_ep_find_next_cap(struct dw_pcie_ep *ep, u8 func_no,
> >  		u8 cap_ptr, u8 cap)
> >  {
> > @@ -759,6 +767,8 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> >
> >  	if (ep->ops->ep_init)
> >  		ep->ops->ep_init(ep);
> > +	if (ep->reset_all_bars)
> > +		dw_pcie_ep_reset_all_bars(pci);
> >
> >  	ret = pci_epc_mem_init(epc, ep->phys_base, ep->addr_size,
> >  			       ep->page_size);
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> > index 9ed9621a12e4..0ad9ed77affb 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -353,6 +353,7 @@ struct dw_pcie_ep {
> >  	void __iomem		*msi_mem;
> >  	phys_addr_t		msi_mem_phys;
> >  	struct pci_epf_bar	*epf_bar[PCI_STD_NUM_BARS];
> > +	bool			reset_all_bars;
> >  };
> >
> >  struct dw_pcie_ops {
> > --
> > 2.25.1
> >




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