[PATCH rtw-next] wifi: rtw88: 8814a: add __packed to ensure efuse map size

[PATCH rtw-next] wifi: rtw88: 8814a: add __packed to ensure efuse map size

[Ping-Ke Shih]

All nested sture/union used by efuse map should be packed. Otherwise, a
arm-linux-gnueabi-gcc compiler might throw errors due to size assertion.

   In file included from include/linux/bitfield.h:10,
                    from include/linux/fortify-string.h:5,
                    from include/linux/string.h:389,
                    from include/linux/uuid.h:11,
                    from include/linux/mod_devicetable.h:14,
                    from include/linux/usb.h:5,
                    from drivers/net/wireless/realtek/rtw88/rtw8814a.c:5:
>> include/linux/build_bug.h:78:41: error: static assertion failed: "sizeof(struct rtw8814a_efuse) == 512"
    #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
                                            ^~~~~~~~~~~~~~

Fixes: 1a7545784642 ("wifi: rtw88: Add rtw8814a.{c,h}")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202604101721.fsv5XmCX-lkp@intel.com/
Cc: Bitterblue Smith <rtl8821cerfe2@gmail.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
---
 drivers/net/wireless/realtek/rtw88/main.h     | 2 +-
 drivers/net/wireless/realtek/rtw88/rtw8814a.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw88/main.h b/drivers/net/wireless/realtek/rtw88/main.h
index 9c0b746540b0..3cc7c2666c1c 100644
--- a/drivers/net/wireless/realtek/rtw88/main.h
+++ b/drivers/net/wireless/realtek/rtw88/main.h
@@ -471,7 +471,7 @@ struct rtw_2g_txpwr_idx {
 	struct rtw_2g_ns_pwr_idx_diff ht_2s_diff;
 	struct rtw_2g_ns_pwr_idx_diff ht_3s_diff;
 	struct rtw_2g_ns_pwr_idx_diff ht_4s_diff;
-};
+} __packed;
 
 struct rtw_5g_ht_1s_pwr_idx_diff {
 #ifdef __LITTLE_ENDIAN
diff --git a/drivers/net/wireless/realtek/rtw88/rtw8814a.h b/drivers/net/wireless/realtek/rtw88/rtw8814a.h
index c57c7c8f915e..a0d9446e2043 100644
--- a/drivers/net/wireless/realtek/rtw88/rtw8814a.h
+++ b/drivers/net/wireless/realtek/rtw88/rtw8814a.h
@@ -51,7 +51,7 @@ struct rtw8814a_efuse {
 	union {
 		struct rtw8814au_efuse u;
 		struct rtw8814ae_efuse e;
-	};
+	} __packed;
 	u8 res5[0x122];			/* 0xde */
 } __packed;
 

base-commit: 929298742bb5dfacd53ea99cf989cc81210f90a3
-- 
2.25.1

Re: [PATCH rtw-next] wifi: rtw88: 8814a: add __packed to ensure efuse map size

[Bitterblue Smith]

On 10/04/2026 16:13, Ping-Ke Shih wrote:
> All nested sture/union used by efuse map should be packed. Otherwise, a
> arm-linux-gnueabi-gcc compiler might throw errors due to size assertion.
> 
>    In file included from include/linux/bitfield.h:10,
>                     from include/linux/fortify-string.h:5,
>                     from include/linux/string.h:389,
>                     from include/linux/uuid.h:11,
>                     from include/linux/mod_devicetable.h:14,
>                     from include/linux/usb.h:5,
>                     from drivers/net/wireless/realtek/rtw88/rtw8814a.c:5:
>>> include/linux/build_bug.h:78:41: error: static assertion failed: "sizeof(struct rtw8814a_efuse) == 512"
>     #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
>                                             ^~~~~~~~~~~~~~
> 
> Fixes: 1a7545784642 ("wifi: rtw88: Add rtw8814a.{c,h}")
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202604101721.fsv5XmCX-lkp@intel.com/
> Cc: Bitterblue Smith <rtl8821cerfe2@gmail.com>
> Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
> ---
>  drivers/net/wireless/realtek/rtw88/main.h     | 2 +-
>  drivers/net/wireless/realtek/rtw88/rtw8814a.h | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 

Thank you for taking care of this. Actually, every chip's efuse struct
has a union like this missing __packed, not just RTL8814A. Most of them
don't have a static_assert.

> diff --git a/drivers/net/wireless/realtek/rtw88/main.h b/drivers/net/wireless/realtek/rtw88/main.h
> index 9c0b746540b0..3cc7c2666c1c 100644
> --- a/drivers/net/wireless/realtek/rtw88/main.h
> +++ b/drivers/net/wireless/realtek/rtw88/main.h
> @@ -471,7 +471,7 @@ struct rtw_2g_txpwr_idx {
>  	struct rtw_2g_ns_pwr_idx_diff ht_2s_diff;
>  	struct rtw_2g_ns_pwr_idx_diff ht_3s_diff;
>  	struct rtw_2g_ns_pwr_idx_diff ht_4s_diff;
> -};
> +} __packed;
>  
>  struct rtw_5g_ht_1s_pwr_idx_diff {
>  #ifdef __LITTLE_ENDIAN
> diff --git a/drivers/net/wireless/realtek/rtw88/rtw8814a.h b/drivers/net/wireless/realtek/rtw88/rtw8814a.h
> index c57c7c8f915e..a0d9446e2043 100644
> --- a/drivers/net/wireless/realtek/rtw88/rtw8814a.h
> +++ b/drivers/net/wireless/realtek/rtw88/rtw8814a.h
> @@ -51,7 +51,7 @@ struct rtw8814a_efuse {
>  	union {
>  		struct rtw8814au_efuse u;
>  		struct rtw8814ae_efuse e;
> -	};
> +	} __packed;
>  	u8 res5[0x122];			/* 0xde */
>  } __packed;
>  
> 
> base-commit: 929298742bb5dfacd53ea99cf989cc81210f90a3

Re: [PATCH rtw-next] wifi: rtw88: 8814a: add __packed to ensure efuse map size

[Ping-Ke Shih]

Bitterblue Smith <rtl8821cerfe2@gmail.com> wrote:

> On 10/04/2026 16:13, Ping-Ke Shih wrote:
> > All nested sture/union used by efuse map should be packed. Otherwise, a
> > arm-linux-gnueabi-gcc compiler might throw errors due to size assertion.
> >
> >    In file included from include/linux/bitfield.h:10,
> >                     from include/linux/fortify-string.h:5,
> >                     from include/linux/string.h:389,
> >                     from include/linux/uuid.h:11,
> >                     from include/linux/mod_devicetable.h:14,
> >                     from include/linux/usb.h:5,
> >                     from drivers/net/wireless/realtek/rtw88/rtw8814a.c:5:
> >>> include/linux/build_bug.h:78:41: error: static assertion failed: "sizeof(struct rtw8814a_efuse) == 512"
> >     #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
> >                                             ^~~~~~~~~~~~~~
> >
> > Fixes: 1a7545784642 ("wifi: rtw88: Add rtw8814a.{c,h}")
> > Reported-by: kernel test robot <lkp@intel.com>
> > Closes:  https://lore.kernel.org/oe-kbuild-all/202604101721.fsv5XmCX-lkp@intel.com/
> > Cc: Bitterblue Smith <rtl8821cerfe2@gmail.com>
> > Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
> > ---
> >  drivers/net/wireless/realtek/rtw88/main.h     | 2 +-
> >  drivers/net/wireless/realtek/rtw88/rtw8814a.h | 2 +-
> >  2 files changed, 2 insertions(+), 2 deletions(-)
> >
> 
> Thank you for taking care of this. Actually, every chip's efuse struct
> has a union like this missing __packed, not just RTL8814A. Most of them
> don't have a static_assert.
> 

Indeed. I added size assetion of efuse map entirely to rtw88 and rtw89 [1],
hoping we can find and address this kind of problem earlier.

[1] https://lore.kernel.org/linux-wireless/20260411072413.1556575-1-pkshih@realtek.com/T/#t