Re: [PATCH] soc: fsl: Remove bogus packed attributes from qman.h

On Tue, Sep 01, 2020 at 01:50:38AM +0000, Leo Li wrote:

Sorry for the late response.  I missed this email previously.

These structures are descriptors used by hardware, we cannot have _ANY_ padding from the compiler.  The compiled result might be the same with or without the __packed attribute for now, but I think keep it there probably is safer for dealing with unexpected alignment requirements from the compiler in the future.

Having conflicting alignment requirements warning might means something is wrong with the structure in certain scenario.  I just tried a ARM64 build but didn't see the warnings.  Could you share the warning you got and the build setup?  Thanks.

Just do a COMPILE_TEST build on x86-64:

In file included from ../drivers/crypto/caam/qi.c:12:
../include/soc/fsl/qman.h:259:1: warning: alignment 1 of ‘struct qm_dqrr_entry’ is less than 8 [-Wpacked-not-aligned]
 } __packed;
 ^
../include/soc/fsl/qman.h:292:2: warning: alignment 1 of ‘struct <anonymous>’ is less than 8 [-Wpacked-not-aligned]
  } __packed ern;
  ^

In any case, those packed markers are completely unnecessary because
those structs contain no holes.

Cheers,
-- 
Email: Herbert Xu [off-list ref]
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