RE: [PATCH] PCI: designware-ep: Fix the Header Type check

[Z.q. Hou]

Hi Rob,

Thanks a lot for your comments!

> -----Original Message-----
> From: Rob Herring [mailto:robh@xxxxxxxxxx]
> Sent: 2020年8月14日 23:51
> To: Z.q. Hou <zhiqiang.hou@xxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx; PCI <linux-pci@xxxxxxxxxxxxxxx>; Lorenzo
> Pieralisi <lorenzo.pieralisi@xxxxxxx>; Bjorn Helgaas
> <bhelgaas@xxxxxxxxxx>; Andrew Murray <amurray@xxxxxxxxxxxxxxxxxxxx>;
> Jingoo Han <jingoohan1@xxxxxxxxx>; Gustavo Pimentel
> <gustavo.pimentel@xxxxxxxxxxxx>
> Subject: Re: [PATCH] PCI: designware-ep: Fix the Header Type check
> 
> On Fri, Aug 14, 2020 at 2:15 AM Zhiqiang Hou <Zhiqiang.Hou@xxxxxxx>
> wrote:
> >
> > From: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
> >
> > The current check will result in the multiple function device fails to
> > initialize. So fix the check by masking out the multiple function bit.
> >
> > Fixes: 0b24134f7888 ("PCI: dwc: Add validation that PCIe core is set
> > to correct mode")
> > Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
> > ---
> >  drivers/pci/controller/dwc/pcie-designware-ep.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c
> > b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > index 4680a51c49c0..4b7abfb1e669 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > @@ -654,7 +654,7 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep
> *ep)
> >         int i;
> >
> >         hdr_type = dw_pcie_readb_dbi(pci, PCI_HEADER_TYPE);
> > -       if (hdr_type != PCI_HEADER_TYPE_NORMAL) {
> > +       if (hdr_type & 0x7f != PCI_HEADER_TYPE_NORMAL) {
> 
> Should have () around 'hdr_type & 0x7f'.
> 
> >                 dev_err(pci->dev,
> >                         "PCIe controller is not set to EP mode
> (hdr_type:0x%x)!\n",
> >                         hdr_type);
> 
> However, shouldn't the printed value be masked too? I'd just do:
> 
> hdr_type = dw_pcie_readb_dbi(pci, PCI_HEADER_TYPE) & 0x7f;
> 
> Perhaps add a #define too. '0x7f' is used in several places.

All these are good suggestions, will make it in next version.

Thanks,
Zhiqiang
 
> 
> Rob