(Sorry for the resend, I forgot to cc the list)
Hi Russell,

It seems that the following change in drivers/serial/8250.c

+
+       /*
+        * Do a quick test to see if we receive an
+        * interrupt when we enable the TX irq.
+        */
+       serial_outp(up, UART_IER, UART_IER_THRI);
+       lsr = serial_in(up, UART_LSR);
+       iir = serial_in(up, UART_IIR);
+       serial_outp(up, UART_IER, 0);
+
+       if (lsr & UART_LSR_TEMT && iir & UART_IIR_NO_INT) {
+               if (!(up->capabilities & UART_BUG_TXEN)) {
+                       up->capabilities |= UART_BUG_TXEN;
+                       pr_debug("ttyS%d - enabling bad tx status 
workarounds\n",
+                                port->line);
+               }
+       } else {
+               up->capabilities &= ~UART_BUG_TXEN;
+       }
+

that was introduced in 2.6.12[1], is causing oopses on some hardware. In
particular Jose Goncalves reported[2] an oops in 2.6.16.38 reproducible
(after a few days of open()/close() on the serial port). He bisected this
to that change -thanks for the long debugging Jose ;)-. and reverting
that part of the 2.6.12 git patch seems to fix the problem.
I was wondering:
- what is the goal of the test?
- could this be CONFIGed ?

Regards,
Frederik

PS: CCing Andrew and Zang Roy-r61911 as they seemed to discuss this in
http://lkml.org/lkml/2006/6/13/21

[1]http://lkml.org/lkml/2005/6/23/266
[2]http://lkml.org/lkml/2007/1/26/157
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to