-----Original Message-----
From: Andrew Murray <redacted>
Sent: 2019年8月27日 21:25
To: Xiaowei Bao <redacted>
Cc: bhelgaas@google.com; robh+dt@kernel.org; mark.rutland@arm.com;
shawnguo@kernel.org; Leo Li [off-list ref]; kishon@ti.com;
lorenzo.pieralisi@arm.co; arnd@arndb.de; gregkh@linuxfoundation.org; M.h.
Lian [off-list ref]; Mingkai Hu [off-list ref]; Roy
Zang [off-list ref]; jingoohan1@gmail.com;
gustavo.pimentel@synopsys.com; linux-pci@vger.kernel.org;
devicetree@vger.kernel.org; linux-kernel@vger.kernel.org;
linux-arm-kernel@lists.infradead.org; linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v2 07/10] PCI: layerscape: Modify the MSIX to the
doorbell way

On Sat, Aug 24, 2019 at 12:08:40AM +0000, Xiaowei Bao wrote:

quoted

quoted

-----Original Message-----
From: Andrew Murray <redacted>
Sent: 2019年8月23日 21:58
To: Xiaowei Bao <redacted>
Cc: bhelgaas@google.com; robh+dt@kernel.org; mark.rutland@arm.com;
shawnguo@kernel.org; Leo Li [off-list ref]; kishon@ti.com;
lorenzo.pieralisi@arm.co; arnd@arndb.de; gregkh@linuxfoundation.org;

M.h.

quoted

quoted

Lian [off-list ref]; Mingkai Hu [off-list ref]; Roy
Zang [off-list ref]; jingoohan1@gmail.com;
gustavo.pimentel@synopsys.com; linux-pci@vger.kernel.org;
devicetree@vger.kernel.org; linux-kernel@vger.kernel.org;
linux-arm-kernel@lists.infradead.org; linuxppc-dev@lists.ozlabs.org
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:

quoted

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?

quoted

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.

Given that dw_pcie_ep_raise_msix_irq is used by pcie-designware-plat.c we
can assume this function at least works for it's use case.

Please update the commit message - It would be helpful to suggest that
dw_pcie_ep_raise_msix_irq was never called in the exisitng driver because
msix_capable was always set to false.

Agree, this is much clearer, I will modify the commit message in the next version patch,
thanks a lot.

Thanks,

Andrew Murray

quoted

quoted

Thanks,

Andrew Murray

quoted

Signed-off-by: Xiaowei Bao <redacted>
---
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,

quoted

 	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);

quoted

quoted

quoted

+		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