From: david.laight.linux@gmail.com
To: Yury Norov <yury.norov@gmail.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Crt Mori <cmo@melexis.com>,
Richard Genoud <richard.genoud@bootlin.com>,
Andy Shevchenko <andriy.shevchenko@intel.com>,
Luo Jie <quic_luoj@quicinc.com>,
Peter Zijlstra <peterz@infradead.org>,
Jakub Kicinski <kuba@kernel.org>,
netdev@vger.kernel.org, "David S . Miller" <davem@davemloft.net>,
Mika Westerberg <mika.westerberg@linux.intel.com>,
Andreas Noever <andreas.noever@gmail.com>,
Yehezkel Bernat <YehezkelShB@gmail.com>,
Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Cc: David Laight <david.laight.linux@gmail.com>
Subject: [PATCH v2 02/16] thunderbolt: Don't pass a bitfield to FIELD_GET
Date: Fri, 12 Dec 2025 19:37:07 +0000 [thread overview]
Message-ID: <20251212193721.740055-3-david.laight.linux@gmail.com> (raw)
In-Reply-To: <20251212193721.740055-1-david.laight.linux@gmail.com>
From: David Laight <david.laight.linux@gmail.com>
None of sizeof(), typeof() or __auto_type can be used with bitfields
which makes it difficult to assign a #define parameter to a local
without promoting char and short to int.
Change:
u32 thunderbolt_version:8;
to the equivalent:
u8 thunderbolt_version;
(and the other three bytes of 'DWORD 4' to match).
This is necessary so that FIELD_GET can use sizeof() to verify 'reg'.
Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
Changes for v2:
- Change structure definition instead of call to FIELD_GET().
FIELD_GET currently uses _Generic() which behaves differently for
gcc and clang (I suspect both are wrong!).
gcc treats 'u32 foo:8' as 'u8', but will take the 'default' for other
widths (which will generate an error in FIED_GET().
clang treats 'u32 foo:n' as 'u32'.
drivers/thunderbolt/tb_regs.h | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index c0bf136236e6..f35f062beb34 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -180,14 +180,14 @@ struct tb_regs_switch_header {
u32 route_hi:31;
bool enabled:1;
/* DWORD 4 */
- u32 plug_events_delay:8; /*
- * RW, pause between plug events in
- * milliseconds. Writing 0x00 is interpreted
- * as 255ms.
- */
- u32 cmuv:8;
- u32 __unknown4:8;
- u32 thunderbolt_version:8;
+ u8 plug_events_delay; /*
+ * RW, pause between plug events in
+ * milliseconds. Writing 0x00 is interpreted
+ * as 255ms.
+ */
+ u8 cmuv;
+ u8 __unknown4;
+ u8 thunderbolt_version;
} __packed;
/* Used with the router thunderbolt_version */
--
2.39.5
next prev parent reply other threads:[~2025-12-12 20:11 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-12 19:37 [PATCH v2 0/16] bitfield: tidy up bitfield.h david.laight.linux
2025-12-12 19:37 ` [PATCH v2 01/16] nfp: Call FIELD_PREP() in NFP_ETH_SET_BIT_CONFIG() wrapper david.laight.linux
2025-12-12 23:10 ` Jakub Kicinski
2025-12-12 19:37 ` david.laight.linux [this message]
2025-12-13 2:28 ` [PATCH v2 02/16] thunderbolt: Don't pass a bitfield to FIELD_GET Yury Norov
2025-12-13 10:01 ` David Laight
2025-12-13 22:14 ` David Laight
2025-12-12 19:37 ` [PATCH v2 03/16] bitmap: Use FIELD_PREP() in expansion of FIELD_PREP_WM16() david.laight.linux
2025-12-17 13:22 ` Nicolas Frattaroli
2025-12-18 0:16 ` Yury Norov
2025-12-18 8:44 ` David Laight
2025-12-19 13:11 ` Nicolas Frattaroli
2026-01-21 16:50 ` Geert Uytterhoeven
2026-01-21 16:52 ` Geert Uytterhoeven
2026-01-21 18:59 ` David Laight
2025-12-12 19:37 ` [PATCH v2 04/16] bitfield: Copy #define parameters to locals david.laight.linux
2025-12-12 19:37 ` [PATCH v2 05/16] bitfield: Merge __field_prep/get() into field_prep/get() david.laight.linux
2025-12-12 19:37 ` [PATCH v2 06/16] bitfield: Remove some pointless casts david.laight.linux
2025-12-12 19:37 ` [PATCH v2 07/16] bitfield: FIELD_MODIFY: Only do a single read/write on the target david.laight.linux
2025-12-12 19:37 ` [PATCH v2 08/16] bitfield: Simplify __BF_FIELD_CHECK_REG() david.laight.linux
2025-12-17 10:26 ` Jonathan Cameron
2025-12-17 22:31 ` David Laight
2025-12-18 0:10 ` Yury Norov
2025-12-28 18:53 ` Andy Shevchenko
2025-12-28 22:50 ` David Laight
2025-12-12 19:37 ` [PATCH v2 09/16] bitfield: Rename __FIELD_PREP/GET() to __BF_FIELD_PREP/GET() david.laight.linux
2025-12-12 19:37 ` [PATCH v2 10/16] bitfield: Split the 'val' check out of __BF_FIELD_CHECK_MASK() david.laight.linux
2025-12-12 19:37 ` [PATCH v2 11/16] bitfield: Common up validation of the mask parameter david.laight.linux
2025-12-14 6:19 ` kernel test robot
2025-12-14 13:17 ` David Laight
2025-12-12 19:37 ` [PATCH v2 12/16] bitfield: Remove leading _ from #define formal parameter names david.laight.linux
2025-12-12 19:37 ` [PATCH v2 13/16] bitfield: Reduce indentation david.laight.linux
2025-12-12 19:37 ` [PATCH v2 14/16] bitfield: Add comment block for the host/fixed endian functions david.laight.linux
2025-12-12 19:37 ` [PATCH v2 15/16] bitfield: Update comments for le/be functions david.laight.linux
2025-12-12 19:37 ` [PATCH v2 16/16] build_bug.h; Remove __BUILD_BUG_ON_NOT_POWER_OF_2() david.laight.linux
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