[PATCH] PCI: dwc: solve returning success but actually failed

[PATCH] PCI: dwc: solve returning success but actually failed

[Zhangjiantao(Kirin,Nanjing)]

When dma_mapping_error returns error because of no enough memory available, dw_pcie_host_init will return success, which will mislead the callers.

Signed-off-by: zhangjianrong <zhangjianrong5@huawei.com>
Signed-off-by: zhangjiantao <water.zhangjiantao@huawei.com>

---
  drivers/pci/controller/dwc/pcie-designware-host.c | 1 +
  1 file changed, 1 insertion(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c
b/drivers/pci/controller/dwc/pcie-designware-host.c
index f4755f3a03be..ac691d733848 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -393,6 +393,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
              if (dma_mapping_error(pci->dev, pp->msi_data)) {
                  dev_err(pci->dev, "Failed to map MSI data\n");
                  pp->msi_data = 0;
+                ret = -1;
                  goto err_free_msi;
              }
          }
--
2.17.1

Re: [PATCH] PCI: dwc: solve returning success but actually failed

[Rob Herring]

On Fri, Mar 4, 2022 at 6:06 AM Zhangjiantao(Kirin,Nanjing)
<water.zhangjiantao@huawei.com> wrote:
>

For the subject, something like: 'PCI: dwc: Fix setting error return
on MSI DMA mapping failure'

> When dma_mapping_error returns error because of no enough memory available, dw_pcie_host_init will return success, which will mislead the callers.

Wrap lines at 72 char.

>

Add a Fixes tag with whatever commit introduced the problem.

> Signed-off-by: zhangjianrong <zhangjianrong5@huawei.com>
> Signed-off-by: zhangjiantao <water.zhangjiantao@huawei.com>

Author and S-o-b names should match.

>
> ---
>   drivers/pci/controller/dwc/pcie-designware-host.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c
> b/drivers/pci/controller/dwc/pcie-designware-host.c
> index f4755f3a03be..ac691d733848 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -393,6 +393,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
>               if (dma_mapping_error(pci->dev, pp->msi_data)) {
>                   dev_err(pci->dev, "Failed to map MSI data\n");
>                   pp->msi_data = 0;
> +                ret = -1;

Use an errno value. ENOMEM seems to be common, but I also see EIO and
EFAULT used.

Rob

Re: [PATCH] PCI: dwc: solve returning success but actually failed

[Bjorn Helgaas]

On Fri, Mar 04, 2022 at 12:06:10PM +0000, Zhangjiantao(Kirin,Nanjing) wrote:
> When dma_mapping_error returns error because of no enough memory available, dw_pcie_host_init will return success, which will mislead the callers.

Wrap to fit in 75 columns, add "()" after function names.
> 
> Signed-off-by: zhangjianrong <zhangjianrong5@huawei.com>
> Signed-off-by: zhangjiantao <water.zhangjiantao@huawei.com>
> 
> ---
>   drivers/pci/controller/dwc/pcie-designware-host.c | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c
> b/drivers/pci/controller/dwc/pcie-designware-host.c
> index f4755f3a03be..ac691d733848 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -393,6 +393,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
>               if (dma_mapping_error(pci->dev, pp->msi_data)) {
>                   dev_err(pci->dev, "Failed to map MSI data\n");
>                   pp->msi_data = 0;
> +                ret = -1;

We should save the return value from dma_mapping_error() and return
*that*, not -1.

Whitespace error (indent with tabs, same as the surrounding code).

>                   goto err_free_msi;
>               }
>           }
> --
> 2.17.1
>