Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH] [v2] platform/surface: aggregator: avoid clang -Wconstant-conversion warning | Date | Fri, 14 May 2021 22:04:36 +0200 |
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From: Arnd Bergmann <arnd@arndb.de>
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@vger.kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- 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 -- 2.29.2
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