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

[Bjorn Helgaas <helgaas@kernel.org>]

On Tue, May 30, 2023 at 06:16:55PM +0800, Sui Jingfeng 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>

I applied this to pci/misc for v6.5, with commit log as below.

But I suspect that it might make your life easier if you include it
with your etnaviv series.  You may be able to avoid adding the
CONFIG_DRM_ETNAVIV_PCI_DRIVER symbol.

If so, feel free to include this patch in that series with my ack:

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

If you do include it in your series, please use the commit log below
and let me know so I can drop it from my queue.

Bjorn


  Author: Sui Jingfeng <suijingfeng@loongson.cn>
  Date:   Wed May 31 18:27:44 2023 +0800

    PCI: Add pci_clear_master() stub for non-CONFIG_PCI
    
    Add a pci_clear_master() stub when CONFIG_PCI is not set so drivers that
    support both PCI and platform devices don't need #ifdefs or extra Kconfig
    symbols for the PCI parts.
    
    [bhelgaas: commit log]
    Fixes: 6a479079c072 ("PCI: Add pci_clear_master() as opposite of pci_set_master()")
    Link: https://lore.kernel.org/r/20230531102744.2354313-1-suijingfeng@loongson.cn
    Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
    Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
    Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
>  include/linux/pci.h | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index d0c19ff0c958..71c85380676c 100644
> --- 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; }
> -- 
> 2.25.1
>