RE: [PATCH v2 07/10] PCI: layerscape: Modify the MSIX to the doorbell way

[Xiaowei Bao]

> -----Original Message-----
> From: Andrew Murray <andrew.murray@xxxxxxx>
> Sent: 2019年8月23日 21:58
> To: Xiaowei Bao <xiaowei.bao@xxxxxxx>
> Cc: bhelgaas@xxxxxxxxxx; robh+dt@xxxxxxxxxx; mark.rutland@xxxxxxx;
> shawnguo@xxxxxxxxxx; Leo Li <leoyang.li@xxxxxxx>; kishon@xxxxxx;
> lorenzo.pieralisi@xxxxxx; arnd@xxxxxxxx; gregkh@xxxxxxxxxxxxxxxxxxx; M.h.
> Lian <minghuan.lian@xxxxxxx>; Mingkai Hu <mingkai.hu@xxxxxxx>; Roy
> Zang <roy.zang@xxxxxxx>; jingoohan1@xxxxxxxxx;
> gustavo.pimentel@xxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linuxppc-dev@xxxxxxxxxxxxxxxx
> Subject: Re: [PATCH v2 07/10] PCI: layerscape: Modify the MSIX to the
> doorbell way
> 
> On Thu, Aug 22, 2019 at 07:22:39PM +0800, Xiaowei Bao wrote:
> > The layerscape platform use the doorbell way to trigger MSIX interrupt
> > in EP mode.
> >
> 
> I have no problems with this patch, however...
> 
> Are you able to add to this message a reason for why you are making this
> change? Did dw_pcie_ep_raise_msix_irq not work when func_no != 0? Or did
> it work yet dw_pcie_ep_raise_msix_irq_doorbell is more efficient?

The fact is that, this driver is verified in ls1046a platform of NXP before, and ls1046a don't
support MSIX feature, so I set the msix_capable of pci_epc_features struct is false,
but in other platform, e.g. ls1088a, it support the MSIX feature, I verified the MSIX
feature in ls1088a, it is not OK, so I changed to another way. Thanks.

> 
> Thanks,
> 
> Andrew Murray
> 
> > Signed-off-by: Xiaowei Bao <xiaowei.bao@xxxxxxx>
> > ---
> > v2:
> >  - No change.
> >
> >  drivers/pci/controller/dwc/pci-layerscape-ep.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pci-layerscape-ep.c
> > b/drivers/pci/controller/dwc/pci-layerscape-ep.c
> > index 8461f62..7ca5fe8 100644
> > --- a/drivers/pci/controller/dwc/pci-layerscape-ep.c
> > +++ b/drivers/pci/controller/dwc/pci-layerscape-ep.c
> > @@ -74,7 +74,8 @@ static int ls_pcie_ep_raise_irq(struct dw_pcie_ep *ep,
> u8 func_no,
> >  	case PCI_EPC_IRQ_MSI:
> >  		return dw_pcie_ep_raise_msi_irq(ep, func_no, interrupt_num);
> >  	case PCI_EPC_IRQ_MSIX:
> > -		return dw_pcie_ep_raise_msix_irq(ep, func_no, interrupt_num);
> > +		return dw_pcie_ep_raise_msix_irq_doorbell(ep, func_no,
> > +							  interrupt_num);
> >  	default:
> >  		dev_err(pci->dev, "UNKNOWN IRQ type\n");
> >  		return -EINVAL;
> > --
> > 2.9.5
> >