On Sun, Dec 06, 2020 at 11:08:14PM +0000, Chaitanya Kulkarni wrote:
> On 12/6/20 11:45, Puranjay Mohan wrote:
> > Callers of pci_find_capability should save the return value in u8.
> > change type of variables from int to u8 to match the specification.
>
> I did not understand this, pci_find_capability() does not return u8.
>
> what is it that we are achieving by changing the variable type ?
>
> This patch will probably also generate type mismatch warning with
>
> certain static analyzers.
There's a patch pending via the PCI tree to change the return type to
u8. We can do one of:
- Ignore this. It only changes something on the stack, so no real
space saving and there's no problem assigning the u8 return value
to the "int".
- The maintainer could ack it and I could merge it via the PCI tree
so it happens in the correct order (after the interface change).
- The PCI core interface change will be merged for v5.11, so we
could hold this until v5.12.
I don't really have a preference. The only place there would really
be a benefit would be if we store the return value in a struct, where
we could potentially save three bytes.
Bjorn
> > Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx>
> > ---
> > drivers/block/mtip32xx/mtip32xx.c | 2 +-
> > drivers/block/skd_main.c | 2 +-
> > 2 files changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
> > index 153e2cdecb4d..da57d37c6d20 100644
> > --- a/drivers/block/mtip32xx/mtip32xx.c
> > +++ b/drivers/block/mtip32xx/mtip32xx.c
> > @@ -3936,7 +3936,7 @@ static DEFINE_HANDLER(7);
> >
> > static void mtip_disable_link_opts(struct driver_data *dd, struct pci_dev *pdev)
> > {
> > - int pos;
> > + u8 pos;
> > unsigned short pcie_dev_ctrl;
> >
> > pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
> > diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
> > index a962b4551bed..16d59569129b 100644
> > --- a/drivers/block/skd_main.c
> > +++ b/drivers/block/skd_main.c
> > @@ -3136,7 +3136,7 @@ MODULE_DEVICE_TABLE(pci, skd_pci_tbl);
> >
> > static char *skd_pci_info(struct skd_device *skdev, char *str)
> > {
> > - int pcie_reg;
> > + u8 pcie_reg;
> >
> > strcpy(str, "PCIe (");
> > pcie_reg = pci_find_capability(skdev->pdev, PCI_CAP_ID_EXP);
>
>
