Re: Wrong GIT author ? also bugs: serial: Add uart driver fori.MX23/28

From: Sascha Hauer
Date: Fri Mar 18 2011 - 09:39:20 EST


Hi Alan,

On Fri, Mar 18, 2011 at 11:29:20AM +0000, Alan Cox wrote:
> > serial: Add auart driver for i.MX23/28
> >
> > Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
>
> You have a few things that need fixing, one of which is quite nasty
>
> > + * Freescale STMP37XX/STMP378X Application UART driver
> > + *
> > + * Author: dmitry pervushin <dimka@xxxxxxxxxxxxxxxxx>
>
> So its signed off by one person and without a signature from the author ?
> Is that intentional
>
> And it git we have
>
> Author: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
>
> which from the header block appears to be untrue ?

The original author indeed is Dmitry with a lot of changes by myself.
Sorry, I didn't hink much while importing it to git, I should probably
have used --author while committing it.


>
> > +static void mxs_auart_rx_chars(struct mxs_auart_port *s)
> > +{
> > + struct tty_struct *tty = s->port.state->port.tty;
> > + u32 stat = 0;
>
> tty may be NULL at this point, in which case your code will try and push
> bits through a NULL pointer and crash
>
> A user can seek to make tty NULL at the right moment by judicious use of
> vhangup, and a remote device can use carrier signals and bit timing to
> mount an attack. See tty_port_tty_get() and/or hold the port lock over
> the IRQ as other drivers do. For the uart stuff I'd hold the port lock as
> the rest of the code in the uart layer sort of assumes that
>
>
> > +static void mxs_auart_settermios(struct uart_port *u,
> > + struct ktermios *termios,
> > + struct ktermios *old)
>
> Minor things here
> - You need to set the termios bits to reflect the mode you actually set.
> So as you don't seem to support mark/space you need to clear the bit,
> ditto h/w flow control if not supported
>
> - You also need to report back the actual baud rate
>
>
> > +static irqreturn_t mxs_auart_irq_handle(int irq, void *context)
> > +{
> > + u32 istatus, istat;
> > + struct mxs_auart_port *s = context;
> > + u32 stat = readl(s->port.membase + AUART_STAT);
>
> Your IRQ handler either needs to take the port lock or have the
> underlying methods do that or their own full locking, you aren't doing
> that.
>

I will send update patches for the comments you made soon.

BTW I wasn't aware of the linux-serial list and the according MAINTAINER
entries do not exist. Should they be added?

Sascha


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