Re: [PATCH] media: ti-vpe: cal: avoid FIELD_GET assertion

From: Laurent Pinchart
Date: Sun Dec 06 2020 - 18:58:49 EST


Hi Arnd,

Thank you for the patch.

On Fri, Dec 04, 2020 at 12:07:30AM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> FIELD_GET() must only be used with a mask that is a compile-time
> constant:
>
> drivers/media/platform/ti-vpe/cal.h: In function 'cal_read_field':
> include/linux/compiler_types.h:320:38: error: call to '__compiletime_assert_247' declared with attribute error: FIELD_GET: mask is not constant
> include/linux/bitfield.h:46:3: note: in expansion of macro 'BUILD_BUG_ON_MSG'
> 46 | BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask), \
> | ^~~~~~~~~~~~~~~~
> drivers/media/platform/ti-vpe/cal.h:220:9: note: in expansion of macro 'FIELD_GET'
> 220 | return FIELD_GET(mask, cal_read(cal, offset));
> | ^~~~~~~~~
>
> The problem here is that the function is not always inlined. Mark it
> __always_inline to avoid the problem.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

This doesn't conflict with the series I've just sent for the CAL driver,
and can thus be applied first or on top. Hans, can I let you handle this
?

> ---
> drivers/media/platform/ti-vpe/cal.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/platform/ti-vpe/cal.h b/drivers/media/platform/ti-vpe/cal.h
> index 4123405ee0cf..20d07311d222 100644
> --- a/drivers/media/platform/ti-vpe/cal.h
> +++ b/drivers/media/platform/ti-vpe/cal.h
> @@ -215,7 +215,7 @@ static inline void cal_write(struct cal_dev *cal, u32 offset, u32 val)
> iowrite32(val, cal->base + offset);
> }
>
> -static inline u32 cal_read_field(struct cal_dev *cal, u32 offset, u32 mask)
> +static __always_inline u32 cal_read_field(struct cal_dev *cal, u32 offset, u32 mask)
> {
> return FIELD_GET(mask, cal_read(cal, offset));
> }

--
Regards,

Laurent Pinchart