RE: [PATCH] soc: fsl: Remove bogus packed attributes from qman.h
From: Leo Li <hidden>
Date: 2020-09-01 01:52:47
Also in:
linux-arm-kernel
-----Original Message----- From: Herbert Xu <herbert@gondor.apana.org.au> Sent: Thursday, July 30, 2020 7:53 AM To: Leo Li <redacted>; linuxppc-dev@lists.ozlabs.org; linux-arm- kernel@lists.infradead.org Subject: [PATCH] soc: fsl: Remove bogus packed attributes from qman.h There are two __packed attributes in qman.h that are both unnecessary and causing compiler warnings because they're conflicting with explicit alignment requirements set on members within the structure.
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. Regards, Leo
quoted hunk ↗ jump to hunk
This patch removes them both. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>diff --git a/include/soc/fsl/qman.h b/include/soc/fsl/qman.h index cfe00e08e85b..d81ff185dc0b 100644 --- a/include/soc/fsl/qman.h +++ b/include/soc/fsl/qman.h@@ -256,7 +256,7 @@ struct qm_dqrr_entry { __be32 context_b; struct qm_fd fd; u8 __reserved4[32]; -} __packed; +}; #define QM_DQRR_VERB_VBIT 0x80 #define QM_DQRR_VERB_MASK 0x7f /* where the verbcontains; */ #define QM_DQRR_VERB_FRAME_DEQUEUE 0x60 /* "this format" */@@ -289,7 +289,7 @@ union qm_mr_entry { __be32 tag; struct qm_fd fd; u8 __reserved1[32]; - } __packed ern; + } ern; struct { u8 verb; u8 fqs; /* Frame Queue Status */ --Email: Herbert Xu [off-list ref] Home Page: https://eur01.safelinks.protection.outlook.com/?url=http:%2F%2Fgondor.ap ana.org.au%2F~herbert%2F&data=02%7C01%7Cleoyang.li%40nxp.com %7Cb69aca8dc53a4030b14b08d8348783a9%7C686ea1d3bc2b4c6fa92cd99c5c3 01635%7C0%7C0%7C637317103931120730&sdata=g3%2FJfa%2FNcuhLD5 SYhbmhno65O1bxisVt2xltu2IMPjQ%3D&reserved=0 PGP Key: https://eur01.safelinks.protection.outlook.com/?url=http:%2F%2Fgondor.ap ana.org.au%2F~herbert%2Fpubkey.txt&data=02%7C01%7Cleoyang.li%4 0nxp.com%7Cb69aca8dc53a4030b14b08d8348783a9%7C686ea1d3bc2b4c6fa9 2cd99c5c301635%7C0%7C0%7C637317103931120730&sdata=uSS2C4cuAL XcCgIhpIORK4EZ1BHHj%2BqAW2Pu%2FLrFKPM%3D&reserved=0