Re: [PATCH 2/5] thunderbolt: Obtain PCI slot number from DROM

[Mika Westerberg]

On Sun, Sep 09, 2018 at 11:42:01PM +0200, Lukas Wunner wrote:
> +struct tb_drom_entry_pci {
> +	/* BYTES 0-1 */
> +	struct tb_drom_entry_header header;
> +	/* BYTE 2 */
> +	u8 unknown:5;
> +	u8 slot:3;
> +	/* BYTES 3-10 are only present on PCIe upstream ports */
> +} __packed;

No need for __packed unless you absolutely are certain the compiler does
not do the right thing. When I submitted the network driver, David
Miller explained this to me and I ended up dropping those.

Also use of bitfields is something we should avoid when touching
hardware/firmware records because compiler here can do all sorts of
tricks.

I know the driver is currently using quite many of them but I think it
is good for the new code not to include them anymore.