From: David Laight <david.laight.linux@gmail.com>
To: Bart Van Assche <bvanassche@acm.org>
Cc: Bean Huo <beanhuo@iokpp.de>, Li Qiang <liqiang01@kylinos.cn>,
linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
alim.akhtar@samsung.com, avri.altman@wdc.com,
James.Bottomley@HansenPartnership.com,
martin.petersen@oracle.com, peter.wang@mediatek.com,
beanhuo@micron.com, can.guo@oss.qualcomm.com,
adrian.hunter@intel.com, tomas.winkler@intel.com
Subject: Re: [PATCH v2 5/6] scsi: ufs: rpmb: Use unaligned accessors for RPMB frames
Date: Thu, 23 Jul 2026 09:12:29 +0100 [thread overview]
Message-ID: <20260723091229.72bc2da8@pumpkin> (raw)
In-Reply-To: <a74b5d01-feaf-47a1-ae40-09f737ad3a6a@acm.org>
On Wed, 22 Jul 2026 06:54:16 -0700
Bart Van Assche <bvanassche@acm.org> wrote:
> On 7/22/26 5:33 AM, Bean Huo wrote:
> > consider Sashiko's suggestion, it's better to add __packed on struct rpmb_frame
> > {}?
>
> Do not add __packed to an entire data structure. Only use it on
> data structure members that need it.
That depends...
If the structure itself can be misaligned in memory then the structure
needs to be packed.
OTOH if there is (for example) a 32bit field on a 16bit boundary then
just marking that field __packed will remove the pad.
The compiler can then use two 16bit instructions to access the data
rather than four 8bit ones.
David
>
> Thanks,
>
> Bart.
>
next prev parent reply other threads:[~2026-07-23 8:12 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-16 6:19 [PATCH 0/5] scsi: ufs: Fix descriptor parsing and invalid input handling liqiang
2026-07-16 6:19 ` [PATCH 1/5] scsi: ufs: core: Validate string descriptors liqiang
2026-07-16 17:47 ` Bart Van Assche
2026-07-17 15:35 ` Li Qiang
2026-07-16 6:19 ` [PATCH 2/5] scsi: ufs: Fix NULL dereferences after tag lookup liqiang
2026-07-16 6:43 ` sashiko-bot
2026-07-16 17:52 ` Bart Van Assche
2026-07-16 6:19 ` [PATCH 3/5] scsi: ufs: core: Validate connected lane counts liqiang
2026-07-16 6:19 ` [PATCH 4/5] scsi: ufs: rpmb: Validate frame before parsing liqiang
2026-07-16 6:28 ` sashiko-bot
2026-07-16 17:58 ` Bart Van Assche
2026-07-16 6:19 ` [PATCH 5/5] scsi: ufs: debugfs: Reserve space for a string terminator liqiang
2026-07-16 17:56 ` Bart Van Assche
2026-07-16 17:42 ` [PATCH 0/5] scsi: ufs: Fix descriptor parsing and invalid input handling Bart Van Assche
2026-07-17 15:16 ` Li Qiang
2026-07-17 15:39 ` [PATCH v2 0/6] " Li Qiang
2026-07-17 15:39 ` [PATCH v2 1/6] scsi: ufs: core: Validate string descriptors Li Qiang
2026-07-20 9:13 ` Peter Wang (王信友)
2026-07-22 18:06 ` Bart Van Assche
2026-07-17 15:39 ` [PATCH v2 2/6] scsi: ufs: Avoid NULL CQE dereference when reporting invalid tags Li Qiang
2026-07-20 9:14 ` Peter Wang (王信友)
2026-07-22 18:07 ` Bart Van Assche
2026-07-17 15:39 ` [PATCH v2 3/6] scsi: ufs: core: Validate connected lane counts Li Qiang
2026-07-17 16:21 ` sashiko-bot
2026-07-17 15:39 ` [PATCH v2 4/6] scsi: ufs: rpmb: Validate request frame length before parsing Li Qiang
2026-07-17 16:32 ` sashiko-bot
2026-07-20 9:15 ` Peter Wang (王信友)
2026-07-22 12:04 ` Bean Huo
2026-07-17 15:39 ` [PATCH v2 5/6] scsi: ufs: rpmb: Use unaligned accessors for RPMB frames Li Qiang
2026-07-17 16:54 ` sashiko-bot
2026-07-20 9:15 ` Peter Wang (王信友)
2026-07-22 12:33 ` Bean Huo
2026-07-22 13:54 ` Bart Van Assche
2026-07-23 8:12 ` David Laight [this message]
2026-07-17 15:39 ` [PATCH v2 6/6] scsi: ufs: debugfs: Reserve space for a string terminator Li Qiang
2026-07-20 9:16 ` Peter Wang (王信友)
2026-07-22 18:08 ` Bart Van Assche
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