Re: [PATCH rtw-next 08/16] wifi: rtw89: add IO offload support via firmware

[Bitterblue Smith <rtl8821cerfe2@gmail.com>]

On 20/04/2026 06:40, Ping-Ke Shih wrote:
> +static void rtw89_fw_cmd_ofld_udelay(struct rtw89_dev *rtwdev, u32 us)
> +{
> +	struct rtw89_fw_cmd_ofld_arg cmd = {
> +		.src = RTW89_FW_CMD_OFLD_SRC_OTHER,
> +		.type = RTW89_FW_CMD_OFLD_DELAY,
> +		.value = us,
> +	};
> +	int ret;
> +
> +	ret = rtw89_fw_cmd_ofld_enqueue(rtwdev, &cmd);
> +	if (ret)
> +		udelay(us);
> +}
> +
> +static void rtw89_fw_cmd_ofld_mdelay(struct rtw89_dev *rtwdev, u32 ms)
> +{
> +	struct rtw89_fw_cmd_ofld_arg cmd = {
> +		.src = RTW89_FW_CMD_OFLD_SRC_OTHER,
> +		.type = RTW89_FW_CMD_OFLD_DELAY,
> +		.value = ms * 1000,
> +	};
> +	int ret;
> +
> +	ret = rtw89_fw_cmd_ofld_enqueue(rtwdev, &cmd);
> +	if (ret)
> +		mdelay(ms);
> +}
This can fail to compile with some kernel configurations because
RTW89_FW_CMD_OFLD_SRC_OTHER (4) doesn't fit in the mask
RTW89_H2C_CMD_OFLD_W0_SRC (GENMASK(0, 1)):

In file included from core.h:10,
                 from cam.h:8,
                 from fw.c:6:
In function ‘le32_encode_bits’,
    inlined from ‘rtw89_fw_cmd_ofld_enqueue’ at fw.c:11655:12,
    inlined from ‘rtw89_fw_cmd_ofld_udelay’ at fw.c:11858:8:
/usr/lib/modules/7.1.3-zen1-1-zen/build/include/linux/bitfield.h:217:17: error: call to ‘__field_overflow’ declared with attribute error: value doesn't fit into mask
  217 |                 __field_overflow();                                     \
      |                 ^~~~~~~~~~~~~~~~~~
/usr/lib/modules/7.1.3-zen1-1-zen/build/include/linux/bitfield.h:235:9: note: in expansion of macro ‘____MAKE_OP’
  235 |         ____MAKE_OP(le##size,u##size,cpu_to_le##size,le##size##_to_cpu) \
      |         ^~~~~~~~~~~
/usr/lib/modules/7.1.3-zen1-1-zen/build/include/linux/bitfield.h:240:1: note: in expansion of macro ‘__MAKE_OP’
  240 | __MAKE_OP(32)
      | ^~~~~~~~~
In function ‘le32_encode_bits’,
    inlined from ‘rtw89_fw_cmd_ofld_enqueue’ at fw.c:11655:12,
    inlined from ‘rtw89_fw_cmd_ofld_mdelay’ at fw.c:11872:8:
/usr/lib/modules/7.1.3-zen1-1-zen/build/include/linux/bitfield.h:217:17: error: call to ‘__field_overflow’ declared with attribute error: value doesn't fit into mask
  217 |                 __field_overflow();                                     \
      |                 ^~~~~~~~~~~~~~~~~~
/usr/lib/modules/7.1.3-zen1-1-zen/build/include/linux/bitfield.h:235:9: note: in expansion of macro ‘____MAKE_OP’
  235 |         ____MAKE_OP(le##size,u##size,cpu_to_le##size,le##size##_to_cpu) \
      |         ^~~~~~~~~~~
/usr/lib/modules/7.1.3-zen1-1-zen/build/include/linux/bitfield.h:240:1: note: in expansion of macro ‘__MAKE_OP’
  240 | __MAKE_OP(32)
      | ^~~~~~~~~

https://github.com/morrownr/rtw89/issues/111
https://github.com/morrownr/rtw89/issues/106

The reports are about the code from that repository, not the kernel,
but I assume the same thing will happen when someone tries to build
kernel 7.2 with the Zen config.

Using the same GCC 16.1.1, this fails on 7.1.3-zen1 but compiles on
7.1.3-arch1 (the standard Arch Linux kernel). This is the difference
between their /proc/config.gz:

3c3
< # Linux/x86 7.1.3-arch1 Kernel Configuration
---
> # Linux/x86 7.1.3-zen1 Kernel Configuration
40a41
> CONFIG_ZEN_INTERACTIVE=y
148a150
> # CONFIG_PREEMPT_RT is not set
218a221
> # CONFIG_SCHED_ALT is not set
270a274
> CONFIG_USER_NS_UNPRIVILEGED=y
290c294,295
< CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE=y
---
> # CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE is not set
> CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3=y
1264c1269
< CONFIG_COMPACT_UNEVICTABLE_DEFAULT=1
---
> CONFIG_COMPACT_UNEVICTABLE_DEFAULT=0
1477a1483
> CONFIG_TCP_CONG_BBR3=m
3057a3064
> CONFIG_VHBA=m

So I guess the error happens when rtw89 is compiled with -O3.