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

[Lorenzo Pieralisi]

On Thu, Aug 29, 2019 at 10:43:18AM +0530, Kishon Vijay Abraham I wrote:
> Gustavo,
> 
> On 27/08/19 6:55 PM, Andrew Murray wrote:
> > On Sat, Aug 24, 2019 at 12:08:40AM +0000, Xiaowei Bao wrote:
> >>
> >>
> >>> -----Original Message-----
> >>> From: Andrew Murray <andrew.murray@xxxxxxx>
> >>> Sent: 2019å8æ23æ 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.
> > 
> > Right, so the existing pci-layerscape-ep.c driver never supported MSIX yet it
> > erroneously had a switch case statement to call dw_pcie_ep_raise_msix_irq which
> > would never get used.
> > 
> > Now that we're adding a platform with MSIX support the existing
> > dw_pcie_ep_raise_msix_irq doesn't work (for this platform) so we are adding a
> > different method.
> 
> Gustavo, can you confirm dw_pcie_ep_raise_msix_irq() works for
> designware as it didn't work for both me and Xiaowei?

This question needs an answer.

Thanks,
Lorenzo