On Wed, Nov 18, 2020 at 12:47:18AM +0530, Puranjay Mohan wrote:
> PCI Capabilities are linked in a list that must appear in the first 256 bytes of config space.
> The Capabilities Pointer register at 0x34 contains the address of the first Capability in the list.
> Each Capability contains an 8 bit "Next Capability Pointer" that is set to 0x00 in the last item of the list.
>
> Change the return type of pci_find_capability() from int to u8 to match the specification.
Nits: Be more specific in subject, e.g., "Return u8 from
pci_find_capability()". Wrap commit log to fit in 78 columns. Add
blank lines between paragraphs. The 0x34 address is accurate but not
relevant to this patch.
> Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx>
> ---
> drivers/pci/pci.c | 4 ++--
> include/linux/pci.h | 4 ++--
> 2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 6d4d5a2f923d..05ac8a493e6b 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -477,9 +477,9 @@ static int __pci_bus_find_cap_start(struct pci_bus *bus,
> * %PCI_CAP_ID_PCIX PCI-X
> * %PCI_CAP_ID_EXP PCI Express
> */
> -int pci_find_capability(struct pci_dev *dev, int cap)
> +u8 pci_find_capability(struct pci_dev *dev, int cap)
> {
> - int pos;
> + u8 pos;
>
> pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type);
Also change the signatures of __pci_bus_find_cap_start(),
__pci_find_next_cap(), __pci_find_next_cap_ttl() to match.
> if (pos)
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 22207a79762c..19a817702ea9 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1063,7 +1063,7 @@ void pci_sort_breadthfirst(void);
>
> /* Generic PCI functions exported to card drivers */
>
> -int pci_find_capability(struct pci_dev *dev, int cap);
> +u8 pci_find_capability(struct pci_dev *dev, int cap);
> int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap);
> int pci_find_ext_capability(struct pci_dev *dev, int cap);
> int pci_find_next_ext_capability(struct pci_dev *dev, int pos, int cap);
> @@ -1719,7 +1719,7 @@ static inline int __pci_register_driver(struct pci_driver *drv,
> static inline int pci_register_driver(struct pci_driver *drv)
> { return 0; }
> static inline void pci_unregister_driver(struct pci_driver *drv) { }
> -static inline int pci_find_capability(struct pci_dev *dev, int cap)
> +static inline u8 pci_find_capability(struct pci_dev *dev, int cap)
> { return 0; }
> static inline int pci_find_next_capability(struct pci_dev *dev, u8 post,
> int cap)
> --
> 2.27.0
>
