Re: [PATCH v3] USB: serial: ftdi_sio: fix setting latency for unprivileged users

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, May 05, 2017 at 05:30:16PM +0200, Anthony Mallet wrote:
> Commit 557aaa7ffab6 ("ft232: support the ASYNC_LOW_LATENCY
> flag") enables unprivileged users to set the FTDI latency timer,
> but there was a logic flaw that skipped sending the corresponding
> USB control message to the device.
> 
> Signed-off-by: Anthony Mallet <anthony.mallet@xxxxxxx>

Now applied with the following amendment to the commit message:

    Specifically, the device latency timer would not be updated until
    next open, something which was later also inadvertently broken by
    commit c19db4c9e49a ("USB: ftdi_sio: set device latency timeout at
    port probe").
    
    A recent commit c6dce2626606 ("USB: serial: ftdi_sio: fix extreme
    low-latency setting") disabled the low-latency mode by default so we
    now need this fix to allow unprivileged users to again enable it.

and an added stable tag.

> ---
>  drivers/usb/serial/ftdi_sio.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git drivers/usb/serial/ftdi_sio.c drivers/usb/serial/ftdi_sio.c
> index d38780f..0e634c1 100644
> --- drivers/usb/serial/ftdi_sio.c
> +++ drivers/usb/serial/ftdi_sio.c
> @@ -1527,9 +1527,9 @@ static int set_serial_info(struct tty_struct *tty,
>  					(new_serial.flags & ASYNC_FLAGS));
>  	priv->custom_divisor = new_serial.custom_divisor;
>  
> +check_and_exit:
>  	write_latency_timer(port);
>  
> -check_and_exit:
>  	if ((old_priv.flags & ASYNC_SPD_MASK) !=
>  	     (priv->flags & ASYNC_SPD_MASK)) {
>  		if ((priv->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)

Thanks,
Johan
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux