RE: [EXT] Re: [PATCHv5 1/6] PCI: mobiveil: Refactor Mobiveil PCIe Host Bridge IP driver

[Z.q. Hou]

Hi Arnd,

Thanks a lot for your comments!

> -----Original Message-----
> From: Arnd Bergmann [mailto:arnd@xxxxxxxx]
> Sent: 2019å4æ12æ 22:39
> To: Z.q. Hou <zhiqiang.hou@xxxxxxx>
> Cc: linux-pci@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> bhelgaas@xxxxxxxxxx; robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx;
> l.subrahmanya@xxxxxxxxxxxxxx; shawnguo@xxxxxxxxxx; Leo Li
> <leoyang.li@xxxxxxx>; lorenzo.pieralisi@xxxxxxx;
> catalin.marinas@xxxxxxx; will.deacon@xxxxxxx; M.h. Lian
> <minghuan.lian@xxxxxxx>; Xiaowei Bao <xiaowei.bao@xxxxxxx>; Mingkai
> Hu <mingkai.hu@xxxxxxx>
> Subject: [EXT] Re: [PATCHv5 1/6] PCI: mobiveil: Refactor Mobiveil PCIe Host
> Bridge IP driver
> 
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> 
> 
> On Fri, Apr 12, 2019 at 11:53 AM Z.q. Hou <zhiqiang.hou@xxxxxxx> wrote:
> 
> > +int mobiveil_pcie_host_probe(struct mobiveil_pcie *pcie)
> >  {
> > -       struct mobiveil_pcie *pcie;
> >         struct pci_bus *bus;
> >         struct pci_bus *child;
> >         struct pci_host_bridge *bridge;
> > -       struct device *dev = &pdev->dev;
> > +       struct device *dev = &pcie->pdev->dev;
> >         resource_size_t iobase;
> >         int ret;
> >
> > -       /* allocate the PCIe port */
> > -       bridge = devm_pci_alloc_host_bridge(dev, sizeof(*pcie));
> > -       if (!bridge)
> > -               return -ENOMEM;
> > -
> > -       pcie = pci_host_bridge_priv(bridge);
> > -
> > -       pcie->pdev = pdev;
> > +       INIT_LIST_HEAD(&pcie->resources);
> >
> >         ret = mobiveil_pcie_parse_dt(pcie);
> >         if (ret) {
> > @@ -928,7 +560,10 @@ static int mobiveil_pcie_probe(struct
> platform_device *pdev)
> >                 return ret;
> >         }
> >
> > -       INIT_LIST_HEAD(&pcie->resources);
> > +       /* allocate the PCIe port */
> > +       bridge = devm_pci_alloc_host_bridge(dev, 0);
> > +       if (!bridge)
> > +               return -ENOMEM;
> >
> 
> > +static int mobiveil_pcie_probe(struct platform_device *pdev) {
> > +       struct mobiveil_pcie *pcie;
> > +       struct device *dev = &pdev->dev;
> > +
> > +       pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
> > +       if (!pcie)
> > +               return -ENOMEM;
> > +
> > +       pcie->pdev = pdev;
> > +
> > +       return mobiveil_pcie_host_probe(pcie); }
> 
> I think you need to pull the allocation of the host structure out into the main
> driver here, to keep both allocations together, otherwise the release function
> will free the mobiveil_pcie structure before freeing the pci_host_bridge if that
> is still in use.

Yes, that will be arranged in v6.

> 
> > +
> > +struct mobiveil_pcie {
> > +       struct platform_device *pdev;
> > +       struct list_head resources;
> 
> These two should not be needed here, as they are already part of the
> pci_host_bridge structure.

The resources list structure has been changed to a pointer to the bridge->windows.
It is better to keep these 2 pointers in the private structure to make it easy to use them
in the PCIe controller driver.

> 
>      Arnd

Regards,
Zhiqiang