poking io port 0x1 probably isn't going to do much good.
Here's what happens after a 'modprobe snd_serial_u16550'
Dave
u16550: can't grab port 0x1
no UART detected at 0x1
Unable to handle kernel NULL pointer dereference at virtual address 00000020
printing eip:
c788b38f
*pde = 00000000
Oops: 0000 [#1]
SMP
CPU: 0
EIP: 0060:[<c788b38f>] Not tainted
EFLAGS: 00010246 (2.6.4-prep)
EIP is at snd_info_unregister+0x5/0x60 [snd]
eax: 00000000 ebx: c1286b1c ecx: 00000000 edx: 00000000
esi: 00000000 edi: c1286b59 ebp: c1286b40 esp: c21cef4c
ds: 007b es: 007b ss: 0068
Process modprobe (pid: 8679, threadinfo=c21ce000 task=c37a0ce0)
Stack: c1286b1c fffffff0 c1286b59 c7889c6d 00000000 c78991f6 c1286b59 c1286b40
c78073f3 00009600 0001c200 00000000 00000000 c7807490 c1286b1c 00000000
00000000 00000000 c031bbd8 c21ce000 c78074b4 c031bbf8 c789ac00 c0138fad
Call Trace:
[<c7889c6d>] snd_card_free+0x163/0x1ed [snd]
[<c78073f3>] snd_serial_probe+0x12a/0x1de [snd_serial_u16550]
[<c7807490>] snd_serial_probe+0x1c7/0x1de [snd_serial_u16550]
[<c78074b4>] alsa_card_serial_init+0xd/0x34 [snd_serial_u16550]
[<c0138fad>] sys_init_module+0x14f/0x25f
[<c02c4567>] syscall_call+0x7/0xb
Code: 8b 40 20 85 c0 74 05 8b 78 34 eb 06 8b 3d 2c 5f 89 c7 bb 90
On Mon, 15 Mar 2004, Dave Jones wrote:
> poking io port 0x1 probably isn't going to do much good.
> Here's what happens after a 'modprobe snd_serial_u16550'
Thanks. I've fixed this problem in our CVS tree. The oops should
be fixed in the current Linus's tree, too.
Jaroslav
-----
Jaroslav Kysela <[email protected]>
Linux Kernel Sound Maintainer
ALSA Project, SuSE Labs
On Mon, Mar 15, 2004 at 05:29:44PM +0100, Jaroslav Kysela wrote:
> On Mon, 15 Mar 2004, Dave Jones wrote:
>
> > poking io port 0x1 probably isn't going to do much good.
> > Here's what happens after a 'modprobe snd_serial_u16550'
>
> Thanks. I've fixed this problem in our CVS tree. The oops should
> be fixed in the current Linus's tree, too.
Hmm, I don't see it at http://cvs.sourceforge.net/viewcvs.py/alsa/alsa-kernel/drivers/serial-u16550.c
Is there somewhere else I should look ?
This was pretty close to top of tree already btw, (only missing
the csets from a few hours ago). I'll test again shortly with top-of-tree.
Dave
--- linux/sound/drivers/serial-u16550.c 13 Jan 2004 17:09:57 -0000 1.20
+++ linux/sound/drivers/serial-u16550.c 15 Mar 2004 17:40:01 -0000 1.21
@@ -342,7 +342,7 @@
unsigned char c;
/* Do some vague tests for the presence of the uart */
- if (io_base == 0) {
+ if (io_base == 0 || io_base == SNDRV_AUTO_PORT) {
return -ENODEV; /* Not configured */
}
@@ -804,10 +804,9 @@
return err;
}
- if (irq >= 0) {
+ if (irq >= 0 && irq != SNDRV_AUTO_IRQ) {
if (request_irq(irq, snd_uart16550_interrupt,
SA_INTERRUPT, "Serial MIDI", (void *) uart)) {
- uart->irq = -1;
snd_printk("irq %d busy. Using Polling.\n", irq);
} else {
uart->irq = irq;