> -----Original Message-----
> From: Andrew Lunn <[email protected]>
> Sent: Thursday, February 19, 2026 2:51 PM
> To: Shenwei Wang <[email protected]>
> Cc: Arnaud POULIQUEN <[email protected]>; Linus Walleij
> <[email protected]>; Bartosz Golaszewski <[email protected]>; Jonathan Corbet
> <[email protected]>; Rob Herring <[email protected]>; Krzysztof Kozlowski
> <[email protected]>; Conor Dooley <[email protected]>; Bjorn Andersson
> <[email protected]>; Mathieu Poirier <[email protected]>; Frank Li
> <[email protected]>; Sascha Hauer <[email protected]>; Shuah Khan
> <[email protected]>; [email protected]; linux-
> [email protected]; [email protected]; Pengutronix Kernel Team
> <[email protected]>; Fabio Estevam <[email protected]>; Peng Fan
> <[email protected]>; [email protected]; linux-
> [email protected]; [email protected]; linux-arm-
> [email protected]; dl-linux-imx <[email protected]>; Bartosz
> Golaszewski <[email protected]>
> Subject: [EXT] Re: [PATCH v8 3/4] gpio: rpmsg: add generic rpmsg GPIO driver
> > > Any reason to use __packed and alignement here?
> > > This structure will be copied in a vring buffer right?
> > >
> >
> > Using __packed together with an explicit alignment is a common pattern
> > for defining communication packets. The goal is to ensure a stable and
> > predictable layout across different architectures and compilers.
>
> Being mostly a netdev person, i can say that the network Maintainers actually
> refuses patches with __packed. If you have designed your protocol correctly,
> defined your structure correctly, you should not need them.
>
The fact is that there are many __packed usages just under the Ethernet
directory.
$ grep -rn __packed drivers/net/ethernet | wc -l
553
Regards,
Shenwei
> We do however accept things like
>
> BUILD_BUG_ON(sizeof(strcut foo) != 8);
>
> just to make sure the compile is doing what you expect.
>
> Andrew
