Re: [PATCH] serial-uartlite: fix build warning

From: Maarten Brock
Date: Fri Mar 18 2016 - 13:49:13 EST


----- Original Message -----
From: Geert Uytterhoeven [mailto:geert@xxxxxxxxxxxxxx]
To: Sudip Mukherjee [mailto:sudipm.mukherjee@xxxxxxxxx]
Cc: Peter Korsgaard [mailto:jacmet@xxxxxxxxxx], Greg Kroah-Hartman [mailto:gregkh@xxxxxxxxxxxxxxxxxxx], Jiri Slaby [mailto:jslaby@xxxxxxxx], linux-kernel@xxxxxxxxxxxxxxx [mailto:linux-kernel@xxxxxxxxxxxxxxx], linux-serial@xxxxxxxxxxxxxxx [mailto:linux-serial@xxxxxxxxxxxxxxx]
Sent: Fri, 18 Mar 2016 13:48:06 +0100
Subject: Re: [PATCH] serial-uartlite: fix build warning


> On Thu, Mar 10, 2016 at 2:14 PM, Sudip Mukherjee
> <sudipm.mukherjee@xxxxxxxxx> wrote:
> > We were getting build warnings about:
> > drivers/tty/serial/uartlite.c: In function âulite_request_portâ:
> > drivers/tty/serial/uartlite.c:348:21: warning: assignment discards
> > 'const' qualifier from pointer target type
> > port->private_data = &uartlite_be;
> > ^
> > drivers/tty/serial/uartlite.c:354:22: warning: assignment discards
> > 'const' qualifier from pointer target type
> > port->private_data = &uartlite_le;
> > ^
> >
> > Fixes: 2905697a82ea ("serial-uartlite: Constify uartlite_be/uartlite_le")
> > Signed-off-by: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxxxxxxx>
>
> Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
>
> Gr{oetje,eeting}s,
>
> Geert

Reverting is not the same as fixing.

Rant:
It is a stupid warning IMHO, but being a compiler writer myself (SDCC) I
understand how it can arise. If you assign some const pointer to a void
pointer without an explicit cast gcc does not complain about the complete
loss of type, but it does warn about losing constness. In general I'd say:
make up your mind; either warn about both or don't warn about either.

Maarten