Re: [PATCH RFC] staging: r8188eu: comment about the chip's packet format

From: Dan Carpenter
Date: Fri Feb 18 2022 - 05:22:56 EST


On Fri, Feb 18, 2022 at 10:22:53AM +0100, Martin Kaiser wrote:
> The structs phy_rx_agc_info and phy_status_rpt define parts of the
> header data that the r8188eu chipset sends to this driver via usb.
>
> Add a comment to clarify that we cannot modify the content of these
> structures and remove seemingly unused fields.
>
> Signed-off-by: Martin Kaiser <martin@xxxxxxxxx>
> ---
>
> Dear all,
>
> I experimented with "cleaning up" these structures and related code before
> discovering that their content comes from usb packets we receive from the
> r8188eu chipset.
>
> Would it make sense to add a word of warning to prevent others from
> repeating this exercise?

Just the fact that these structs are endian means they're from the
firmware or the network.

If a struct has a pointer in it, then it's rarely part of the UAPI but
if it has endian data then it probably is.

regards,
dan carpenter