Hi,
On 23-09-2019 00:29, Maximilian Luz wrote:
Hi all,
On 9/20/19 5:00 PM, Hans de Goede wrote:
So as promised I've given this patch a try, unfortunately it breaks
existing users of ACPI serdev device instantation.
After adding this patch "ls /sys/bus/serial/devices" is empty,
where as before it gives:
[root@dhcp-45-50 ~]# ls -l /sys/bus/serial/devices/
total 0
lrwxrwxrwx. 1 root root 0 Sep 20 16:43 serial0 ->
../../../devices/pci0000:00/8086228A:00/serial0
lrwxrwxrwx. 1 root root 0 Sep 20 16:43 serial0-0 ->
../../../devices/pci0000:00/8086228A:00/serial0/serial0-0
And since the serdev is missing bluetooth does not work.
Thanks to some testing by Hans, it turns out that the reason for this is
that acpi_walk_resources fails with AE_AML_INVALID_RESOURCE_TYPE for a
specific device. If anyone is interested, the _CRS of the device in
question is
Method (_CRS, 0, NotSerialized) // _CRS: Current Resource Settings
{
Name (NAM, Buffer (0x14)
{
"\\_SB.PCI0.SDHB.BRC1"
})
Name (SPB, Buffer (0x0C)
{
/* 0000 */ 0x8E, 0x1D, 0x00, 0x01, 0x00, 0xC0, 0x02, 0x00,
/* 0008 */ 0x00, 0x01, 0x00, 0x00
})
Name (END, ResourceTemplate ()
{
})
Concatenate (SPB, NAM, Local0)
Concatenate (Local0, END, Local1)
Return (Local1)
}
To solve this, I propose ignoring errors that occur when evaluating the
_CRS method. Note that with the previously discussed change for v2,
where we will only look at the first device in _CRS, we should be able
to handle errors from the actual serdev device allocation separately
(and only ignore AML evaluation errors).
Further, I think it might also make sense to move the status and
already-enumerated checks out of acpi_serdev_register_device to before
looking at _CRS.
Ack, this is what drivers/i2c/i2c-core-acpi.c is doing and more in general
all ACPI enumeration code always first checks _STA before doing anything
else, so I think it would be best to do this here too.
Actually I think it might be best to fully copy how drivers/i2c/i2c-core-acpi.c
does things.
Regards,
Hans
