Re: [PATCH net-next v7 5/6] stmmac: dwmac-mediatek: add support for mt8195

On Thu, 9 Dec 2021 09:48:25 +0800 Biao Huang wrote:

Sorry for some typo in previous reply, fix it here.

All these warning lines share a similar semantics:
delay_val |= FIELD_PREP(xxx, !!val);

and, should come from the expansion of FIELD_PREP in
include/linux/bitfiled.h:

  FIELD _PREP --> __BF_FILED_CHECK --> "~((_mask) >> __bf_shf(_mask)) &
(_val) : 0,"

===============================================================
__BF_FILED_CHECK {
...
  BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ?           \
                   ~((_mask) >> __bf_shf(_mask)) & (_val) : 0, \
                   _pfx "value too large for the field"); \ ...
===============================================================

Should I fix it by converting
  delay_val |= FIELD_PREP(ETH_DLY_TXC_ENABLE, !!mac_delay->tx_delay);
to
  en_val = !!mac_delay->tx_delay;
  delay_val |= FIELD_PREP(ETH_DLY_TXC_ENABLE, en_val);

or other suggestions for these warnings?

I see, thanks for explaining. The code is fine, we can simply ignore
this warning IMHO.