On Wed, Nov 24, 2021 at 07:34:24PM +0530, Manivannan Sadhasivam wrote:
> Fix the below sparse warning due to the use of incorrect initializer
> data type (u16) for bdf_be variable that receives the return value of
> cpu_to_be16(). The correct type should be __be16.
I think the patch looks OK, but the reason to change this is not to
"fix the warning". The reason is to fix the *problem*, i.e.,
cpu_to_be16() returns "__be16", which is incompatible with "u16".
The warning is only a helpful hint, and should not be part of the
subject line. "cpu_to_be16" or "iommu-map" would be much more
useful information in the subject.
I'm also curious why pcie-qcom.c is the only driver that does this.
"iommu-map" is not specific to qcom, but no other drivers do similar
things with it.
> sparse warnings: (new ones prefixed by >>)
> >> drivers/pci/controller/dwc/pcie-qcom.c:1305:30: sparse: sparse: incorrect type in initializer (different base types) @@ expected unsigned short [usertype] bdf_be @@ got restricted __be16 [usertype] @@
> drivers/pci/controller/dwc/pcie-qcom.c:1305:30: sparse: expected unsigned short [usertype] bdf_be
> drivers/pci/controller/dwc/pcie-qcom.c:1305:30: sparse: got restricted __be16 [usertype]
>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-qcom.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c
> index 8a7a300163e5..6c3b034e9946 100644
> --- a/drivers/pci/controller/dwc/pcie-qcom.c
> +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> @@ -1312,7 +1312,7 @@ static int qcom_pcie_config_sid_sm8250(struct qcom_pcie *pcie)
>
> /* Look for an available entry to hold the mapping */
> for (i = 0; i < nr_map; i++) {
> - u16 bdf_be = cpu_to_be16(map[i].bdf);
> + __be16 bdf_be = cpu_to_be16(map[i].bdf);
> u32 val;
> u8 hash;
>
> --
> 2.25.1
>
