RE: [PATCHv3 17/27] PCI: mobiveil: fix the checking of valid device

Hi Subbu,

Thanks a lot for your comments!

-----Original Message-----
From: Subrahmanya Lingappa <redacted>
Sent: 2019年2月8日 20:41
To: Z.q. Hou <zhiqiang.hou@nxp.com>
Cc: linux-pci@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
devicetree@vger.kernel.org; linux-kernel@vger.kernel.org;
bhelgaas@google.com; robh+dt@kernel.org; mark.rutland@arm.com;
shawnguo@kernel.org; Leo Li [off-list ref];
lorenzo.pieralisi@arm.com; catalin.marinas@arm.com;
will.deacon@arm.com; Mingkai Hu [off-list ref]; M.h. Lian
[off-list ref]; Xiaowei Bao [off-list ref]
Subject: Re: [PATCHv3 17/27] PCI: mobiveil: fix the checking of valid device

ZQ,

On Tue, Jan 29, 2019 at 1:40 PM Z.q. Hou [off-list ref] wrote:

quoted

From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>

Avoid to issue CFG transactions to link partner when the PCIe link is
not up. And allow CFG transactions to all functions of Endpoint
implemented multiple functions.

Fixes: 9af6bcb11e12 ("PCI: mobiveil: Add Mobiveil PCIe Host Bridge IP
driver")
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Reviewed-by: Minghuan Lian <Minghuan.Lian@nxp.com>
---
V3:
 - No change

 drivers/pci/controller/mobiveil/pcie-mobiveil-host.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/mobiveil/pcie-mobiveil-host.c

b/drivers/pci/controller/mobiveil/pcie-mobiveil-host.c
index dc5324d94466..1ae82e790562 100644

--- a/drivers/pci/controller/mobiveil/pcie-mobiveil-host.c
+++ b/drivers/pci/controller/mobiveil/pcie-mobiveil-host.c

@@ -29,6 +29,10 @@ static bool mobiveil_pcie_valid_device(struct

pci_bus *bus, unsigned int devfn)  {
        struct mobiveil_pcie *pcie = bus->sysdata;

+       /* If there is no link, then there is no device */
+       if (bus->number > pcie->rp.root_bus_nr

&& !mobiveil_pcie_link_up(pcie))

quoted

+               return false;
+
        /* Only one device down on each root port */
        if ((bus->number == pcie->rp.root_bus_nr) && (devfn > 0))
                return false;

@@ -37,7 +41,7 @@ static bool mobiveil_pcie_valid_device(struct pci_bus

*bus, unsigned int devfn)

quoted

         * Do not read more than one device on the bus directly
         * attached to RC
         */
-       if ((bus->primary == pcie->rp.root_bus_nr) && (devfn > 0))
+       if ((bus->primary == pcie->rp.root_bus_nr) && (PCI_SLOT(devfn)
+ > 0))

here change "primary" to "number", as it's a bug in the original driver too.

No, I think it should not change to "number", as this is to check the EP directly attached to RC, so if we change it to "bus->number", the "pcie->rp.root_bus_nr" should be changed to "pcie->rp.root_bus_nr +1" correspondingly.

quoted

                return false;

        return true;
--
2.17.1

Thanks,
Zhiqiang
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