Re: [PATCH] linux/pci.h: add a dummy implement for pci_clear_master()

[Sui Jingfeng <suijingfeng@loongson.cn>]

Hi,

thanks a lot.

On 2023/5/31 15:04, Geert Uytterhoeven wrote:
> Hi Sui,
>
> On Tue, May 30, 2023 at 12:21 PM Sui Jingfeng <suijingfeng@loongson.cn> wrote:
>> As some arch(m68k for example) doesn't have config_pci enabled, drivers[1]
>> call pci_clear_master() without config_pci guard can not built.
>>
>>     drivers/gpu/drm/etnaviv/etnaviv_pci_drv.c:
>>     In function 'etnaviv_gpu_pci_fini':
>>>> drivers/gpu/drm/etnaviv/etnaviv_pci_drv.c:32:9:
>>     error: implicit declaration of function 'pci_clear_master';
>>     did you mean 'pci_set_master'? [-Werror=implicit-function-declaration]
>>        32 |         pci_clear_master(pdev);
>>           |         ^~~~~~~~~~~~~~~~
>>           |         pci_set_master
>>     cc1: some warnings being treated as errors
>>
>> [1] https://patchwork.freedesktop.org/patch/539977/?series=118522&rev=1
>>
>> Reported-by: kernel test robot <lkp@intel.com>
>> Closes: https://lore.kernel.org/oe-kbuild-all/202305301659.4guSLavL-lkp@intel.com/
>> Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
> Thanks for your patch!
>
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -1904,6 +1904,7 @@ static inline int pci_dev_present(const struct pci_device_id *ids)
>>   #define pci_dev_put(dev)       do { } while (0)
>>
>>   static inline void pci_set_master(struct pci_dev *dev) { }
>> +static inline void pci_clear_master(struct pci_dev *dev) { }
>>   static inline int pci_enable_device(struct pci_dev *dev) { return -EIO; }
>>   static inline void pci_disable_device(struct pci_dev *dev) { }
>>   static inline int pcim_enable_device(struct pci_dev *pdev) { return -EIO; }
> Makes perfect sense, given there has been a dummy for pci_set_master()
> since the git stone age. Apparently adding the dummy was forgotten
> when pci_clear_master() was introduced.
>
> Fixes: 6a479079c07211bf ("PCI: Add pci_clear_master() as opposite of
> pci_set_master()")
> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
>
> Gr{oetje,eeting}s,
>
>                          Geert
>
-- 
Jingfeng