Re: acpi: bad write: (was: Re: My snd_ich working well)

Ben Kaduk wrote:
> On 4/4/06, Nate Lawson <nate_at_root.org> wrote:
>> /*
>>   * Some BIOS vendors use AML to read/write directly to IO space.  This
>>   * can cause a problem if such accesses interfere with the OS's access to
>>   * the same ports.  Windows XP and newer systems block accesses to certain
>>   * IO ports.  We print a message or block accesses based on a tunable.
>>   */
>> static int illegal_bios_ports[] = {
>>         0x000, 0x00f,   /* DMA controller 1 */
>>         0x020, 0x021,   /* PIC */
>>         0x040, 0x043,   /* Timer 1 */
>>         0x048, 0x04b,   /* Timer 2 failsafe */
>>         0x070, 0x071,   /* CMOS and RTC */
>>         0x074, 0x076,   /* Extended CMOS */
>>         0x081, 0x083,   /* DMA1 page registers */
>>         0x087, 0x087,   /* DMA1 ch0 low page */
>>         0x089, 0x08b,   /* DMA2 ch2 (0x89), ch3 low page (0x8a, 0x8b) */
>>         0x08f, 0x091,   /* DMA2 low page refresh (0x8f) */
>>                         /* Arb ctrl port, card select feedback (0x90, 0x91) */
>>         0x093, 0x094,   /* System board setup */
>>         0x096, 0x097,   /* POS channel select */
>>         0x0a0, 0x0a1,   /* PIC (cascaded) */
>>         0x0c0, 0x0df,   /* ISA DMA */
>>         0x4d0, 0x4d1,   /* PIC ELCR (edge/level control) */
>>         0xcf8, 0xcff,   /* PCI config space. Microsoft adds 0xd00 also but
>>                            that seems incorrect. */
>>         -1, -1
>> };
>>
> 
> Hi Nate,
> 
> As posted earlier, I'm getting these acpi: bad write
> messages spamming my console, with port 0x086 instead of Angka's
> 0x073.  I don't see 0x086 in the above list, though, so I'm a bit
> confused.

This message would have been triggered by the off-by-one error before my 
fix (86 is just below 87, which is on the list).

The check is now:
if ((addr >= port[0] && addr <= port[1]) ||
     (addr < port[0] && addr + (width / 8) > port[0]))

Which gives (with addr = 86 and width = 8):
86 >= 87 ...  FALSE
86 < 87 (TRUE) && 86 + 1 > 87 (FALSE) ... FALSE

You can try it yourself with (play around with addr and width):

main()
{
int addr = 0x86;
int width = 8;
int port[2] = { 0x87, 0x87 };

if ((addr >= port[0] && addr <= port[1]) ||
     (addr < port[0] && addr + (width / 8) > port[0]))
         printf("BUGGY BUGGY BIOS\n");
else
         printf("KRAD!\n");
}

So the code is correct.  Please be sure you have the right version that 
matches this code snippet above and recompile your acpi module (or 
entire kernel) and reinstall it.

> I have revision 1.120 of src/sys/dev/acpica/Osd/OsdHardware.c

The correct version is 1.20.

Thanks,
-- 
Nate