Messages in this thread Patch in this message | | | Subject | Re: Serial issue | From | Lee Revell <> | Date | Fri, 18 Aug 2006 13:55:33 -0400 |
| |
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/
| |