[PATCH2] PCI: dwc: solve returning success but actually failed

["Zhangjiantao(Kirin,Nanjing)" <water.zhangjiantao@huawei.com>]

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

Fixes: 07940c369a6b ("PCI: dwc: Fix MSI page leakage in suspend/resume")

Signed-off-by: Jiantao Zhang <water.zhangjiantao@huawei.com>
Signed-off-by: Jianrong Zhang <zhangjianrong5@huawei.com>
---
  drivers/pci/controller/dwc/pcie-designware-host.c | 3 ++-
  1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c
b/drivers/pci/controller/dwc/pcie-designware-host.c
index f4755f3a03be..9dcb51728dd1 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -390,7 +390,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
                                sizeof(pp->msi_msg),
                                DMA_FROM_DEVICE,
                                DMA_ATTR_SKIP_CPU_SYNC);
-            if (dma_mapping_error(pci->dev, pp->msi_data)) {
+            ret = dma_mapping_error(pci->dev, pp->msi_data);
+            if (ret) {
                  dev_err(pci->dev, "Failed to map MSI data\n");
                  pp->msi_data = 0;
                  goto err_free_msi;
--
2.17.1

Jiantao Zhang

On 2022/3/5 5:39, Bjorn Helgaas wrote:
> 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
>>
> .