> -----Original Message----- > From: Bjorn Helgaas <helgaas@xxxxxxxxxx> > Sent: Saturday, September 9, 2023 1:23 AM > To: D M, Sharath Kumar <sharath.kumar.d.m@xxxxxxxxx> > Cc: lpieralisi@xxxxxxxxxx; kw@xxxxxxxxx; robh@xxxxxxxxxx; > bhelgaas@xxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; dinguyen@xxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx > Subject: Re: [PATCH v2 1/2] PCI: altera: refactor driver for supporting new > platform > > On Fri, Sep 08, 2023 at 01:40:13PM +0000, D M, Sharath Kumar wrote: > > > -----Original Message----- > > > From: Bjorn Helgaas <helgaas@xxxxxxxxxx> On Fri, Sep 08, 2023 at > > > 09:09:34AM +0000, D M, Sharath Kumar wrote: > > > > > -----Original Message----- > > > > > From: Bjorn Helgaas <helgaas@xxxxxxxxxx> ... > > > > > > > > > + int (*ep_read_cfg)(struct altera_pcie *pcie, u8 busno, > > > > > > + unsigned int devfn, int where, int size, u32 > *value); > > > > > > + int (*ep_write_cfg)(struct altera_pcie *pcie, u8 busno, > > > > > > + unsigned int devfn, int where, int size, u32 > value); > > > > > > > > > > "ep_read_cfg" isn't the ideal name because it suggests > > > > > "endpoint", but it may be either an endpoint or a switch > > > > > upstream port. The rockchip driver uses "other", which isn't > > > > > super descriptive either but > > > might be better. > > > > > > > > > Ok will change to "nonrp_read_cfg" ? > > > > > > I think the important point is not whether it's a Root Port or not, > > > but whether it's on the root *bus* or not. In other words, I think > > > the driver has to determine whether to generate a Type 0 (targeting > > > something on the root > > > bus) or a Type 1 (targeting something below a > > > bridge) config transaction (see PCI-to-PCI Bridge spec r1.2, sec 3.1.2.1). > > > > > > There can be non-Root Ports on the root bus, so "nonrp" doesn't seem > > > quite right. "Other" would be OK, since that's already used by other > drivers. > > > Maybe "type0" and "type1" would be better and would fit well with > > > the root_bus_nr check you use to distinguish them? > > > > > Situation is > > Root port configuration space - memory mapped Non root port > > configuration space - indirect access/proprietary access > > Type 0 for devices directly connected to root port > > Type 1 for others > > "mm", "ind"? Memory mapped - configuration registers available at pre defined address
