lkml.org 
[lkml]   [2016]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] serial: 8250_dw: fix wrong logic in dw8250_check_lcr()
From
Date
On Fri, 2016-04-01 at 17:06 +0800, Kefeng Wang wrote:
> Commit cdcea058e510("serial: 8250_dw: Avoid serial_outx code
> duplicate
> with new dw8250_check_lcr()") introduce a wrong logic when write val
> to
> LCR reg. When CONFIG_64BIT enabled, __raw_writeq is used
> unconditionally.
>
> But for !PORT_OCTEON, we better to use coincident write func.
>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
>
> We met following calltrace twice, if the change is not necessary,
> correct me,
> and any advice will be appreciated, thanks.

So, does this fix you issue? If it does than perhaps you need to Cc
stable@ and put Fixes tag as well.

> --- a/drivers/tty/serial/8250/8250_dw.c
> +++ b/drivers/tty/serial/8250/8250_dw.c
> @@ -104,15 +104,16 @@ static void dw8250_check_lcr(struct uart_port
> *p, int value)
>   dw8250_force_idle(p);
>  
>  #ifdef CONFIG_64BIT
> - __raw_writeq(value & 0xff, offset);
> -#else
> + if (p->type == PORT_OCTEON)
> + __raw_writeq(value & 0xff, offset);
> + else
> +#endif

You may also get rid of this one, like

if (IS_ENABLED(CONFIG_64BIT) && p->type == PORT_OCTEON)
 ...
else if
...

>   if (p->iotype == UPIO_MEM32)
>   writel(value, offset);
>   else if (p->iotype == UPIO_MEM32BE)
>   iowrite32be(value, offset);
>   else
>   writeb(value, offset);
> -#endif
>   }
>   /*
>    * FIXME: this deadlocks if port->lock is already held

--
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

\
 
 \ /
  Last update: 2016-04-01 12:21    [W:0.054 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site