lkml.org 
[lkml]   [2006]   [Aug]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: Serial issue
From
Date
On Fri, 2006-08-18 at 10:44 -0500, Paul Fulghum wrote:
> On Thu, 2006-08-17 at 20:47 -0400, Lee Revell wrote:
> > I've found a weird serial bug. My host is a Via EPIA M-6000 running
> > 2.6.17 connected to a PPC Yosemite board running 2.6.13.
> >
> > In all cases the serial console works great. But, with the default
> > setting of IRQ 4, Kermit file transfers via the serial interface simply
> > time out. However if I use polling mode (setserial /dev/ttyS0 irq 0 on
> > the host), file transfers work.
> >
> > When set to IRQ 4, the interrupt count does increase.
> >
> > # cat /proc/tty/driver/serial
> > serinfo:1.0 driver revision:
> > 0: uart:16550A port:000003F8 irq:4 tx:267 rx:667 DSR|CD
> > [...]
> >
> > Any ideas? I'm guessing it might be a quirk of the VIA chipset?
>
> You mention serial console. Hasn't there been some changes
> related to reenabling the THRE interrupt after sending
> console data? IIRC the changes fixed transmit stalls on
> some machines but broke things on other machine.

I tried Paul's suggestion:

--- drivers/serial/8250.c~ 2006-06-17 21:49:35.000000000 -0400
+++ drivers/serial/8250.c 2006-08-18 12:57:16.000000000 -0400
@@ -2263,7 +2263,7 @@
* and restore the IER
*/
wait_for_xmitr(up, BOTH_EMPTY);
- serial_out(up, UART_IER, ier);
+ serial_out(up, UART_IER, ier | UART_IER_THRI);

if (locked)
spin_unlock_irqrestore(&up->port.lock, flags);

But it had no effect.

Could it be a hardware-specific bug? After all VIA chipsets are
notorious for interrupts not working right.

Any other suggestions?

Lee

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-08-18 19:59    [W:0.071 / U:0.096 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site