Re: [PATCH v6 17/20] PCI: dwc: Introduce generic resources getter

[Serge Semin]

Hi Yoshihiro

On Wed, Nov 09, 2022 at 02:17:45AM +0000, Yoshihiro Shimoda wrote:
> Hi Serge,
> 
> > From: Serge Semin, Sent: Tuesday, November 8, 2022 5:50 AM
> > 
> > Currently the DW PCIe Root Port and Endpoint CSR spaces are retrieved in
> > the separate parts of the DW PCIe core driver. It doesn't really make
> > sense since the both controller types have identical set of the core CSR
> > regions: DBI, DBI CS2 and iATU/eDMA. Thus we can simplify the DW PCIe Host
> > and EP initialization methods by moving the platform-specific registers
> > space getting and mapping into a common method. It gets to be even more
> > justified seeing the CSRs base address pointers are preserved in the
> > common DW PCIe descriptor. Note all the OF-based common DW PCIe settings
> > initialization will be moved to the new method too in order to have a
> > single function for all the generic platform properties handling in single
> > place.
> > 
> > A nice side-effect of this change is that the pcie-designware-host.c and
> > pcie-designware-ep.c drivers are cleaned up from all the direct dw_pcie
> > storage modification, which makes the DW PCIe core, Root Port and Endpoint
> > modules more coherent.
> > 
> > Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
> > Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
> > 
> > ---
> > 
> > Changelog v3:
> > - This is a new patch created on v3 lap of the series.
> > 
> > Changelog v4:
> > - Convert the method name from dw_pcie_get_res() to
> >   dw_pcie_get_resources(). (@Bjorn)
> > ---
> >  .../pci/controller/dwc/pcie-designware-ep.c   | 26 +------
> >  .../pci/controller/dwc/pcie-designware-host.c | 15 +---
> >  drivers/pci/controller/dwc/pcie-designware.c  | 75 ++++++++++++++-----
> >  drivers/pci/controller/dwc/pcie-designware.h  |  3 +
> >  4 files changed, 65 insertions(+), 54 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > index 237bb01d7852..80a64b63c055 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > @@ -13,8 +13,6 @@
> >  #include <linux/pci-epc.h>
> >  #include <linux/pci-epf.h>
> > 
> > -#include "../../pci.h"
> > -
> >  void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
> >  {
> >  	struct pci_epc *epc = ep->epc;
> > @@ -688,29 +686,14 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
> >  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> >  	struct device *dev = pci->dev;
> >  	struct platform_device *pdev = to_platform_device(dev);
> > -	struct device_node *np = dev->of_node;
> 
> Removing this np causes the following build error if CONFIG_PCIE_DW_EP is enabled:
> ---
>   CC      drivers/pci/controller/dwc/pcie-designware-ep.o
> drivers/pci/controller/dwc/pcie-designware-ep.c: In function 'dw_pcie_ep_init':
> drivers/pci/controller/dwc/pcie-designware-ep.c:751:35: error: 'np' undeclared (first use in this function); did you mean 'ep'?
>   751 |         ret = of_property_read_u8(np, "max-functions", &epc->max_functions);
>       |                                   ^~
>       |                                   ep
> drivers/pci/controller/dwc/pcie-designware-ep.c:751:35: note: each undeclared identifier is reported only once for each function it appears in
> ---
> 
> So, we should keep the np or use "dev->of_node" to the of_property_read_u8().

Indeed. Thanks for noticing that. I'll fix it in v7.

-Sergey

> 
> Best regards,
> Yoshihiro Shimoda
>