On 14/05/2021 22:04, Arnd Bergmann wrote:
From: Arnd Bergmann <arnd@xxxxxxxx>
Clang complains about the assignment of SSAM_ANY_IID to
ssam_device_uid->instance:
drivers/platform/surface/surface_aggregator_registry.c:478:25: error: implicit conversion from 'int' to '__u8' (aka 'unsigned char') changes value from 65535 to 255 [-Werror,-Wconstant-conversion]
{ SSAM_VDEV(HUB, 0x02, SSAM_ANY_IID, 0x00) },
~ ^~~~~~~~~~~~
include/linux/surface_aggregator/device.h:71:23: note: expanded from macro 'SSAM_ANY_IID'
#define SSAM_ANY_IID 0xffff
^~~~~~
include/linux/surface_aggregator/device.h:126:63: note: expanded from macro 'SSAM_VDEV'
SSAM_DEVICE(SSAM_DOMAIN_VIRTUAL, SSAM_VIRTUAL_TC_##cat, tid, iid, fun)
^~~
include/linux/surface_aggregator/device.h:102:41: note: expanded from macro 'SSAM_DEVICE'
.instance = ((iid) != SSAM_ANY_IID) ? (iid) : 0, \
^~~
The assignment doesn't actually happen, but clang checks the type limits
before checking whether this assignment is reached. Replace the ?:
operator with a __builtin_choose_expr() invocation that avoids the
warning for the untaken part.
Fixes: eb0e90a82098 ("platform/surface: aggregator: Add dedicated bus and device type")
Cc: platform-driver-x86@xxxxxxxxxxxxxxx
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Thanks! This looks good to me.
Reviewed-by: Maximilian Luz <luzmaximilian@xxxxxxxxx>
---
v2: use __builtin_choose_expr() instead of a cast to shut up the warning
---
include/linux/surface_aggregator/device.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/linux/surface_aggregator/device.h b/include/linux/surface_aggregator/device.h
index 4441ad667c3f..6ff9c58b3e17 100644
--- a/include/linux/surface_aggregator/device.h
+++ b/include/linux/surface_aggregator/device.h
@@ -98,9 +98,9 @@ struct ssam_device_uid {
| (((fun) != SSAM_ANY_FUN) ? SSAM_MATCH_FUNCTION : 0), \
.domain = d, \
.category = cat, \
- .target = ((tid) != SSAM_ANY_TID) ? (tid) : 0, \
- .instance = ((iid) != SSAM_ANY_IID) ? (iid) : 0, \
- .function = ((fun) != SSAM_ANY_FUN) ? (fun) : 0 \
+ .target = __builtin_choose_expr((tid) != SSAM_ANY_TID, (tid), 0), \
+ .instance = __builtin_choose_expr((iid) != SSAM_ANY_IID, (iid), 0), \
+ .function = __builtin_choose_expr((fun) != SSAM_ANY_FUN, (fun), 0)
/**
* SSAM_VDEV() - Initialize a &struct ssam_device_id as virtual device with
