Messages in this thread | | | Date | Sat, 4 Feb 2012 09:45:43 +0100 | From | Jean Delvare <> | Subject | Re: [PATCH 1/3] mfd: Add LPC driver for Intel ICH chipsets |
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Hi Aaron,
On Fri, 03 Feb 2012 16:50:28 -0600 (CST), Aaron Sierra wrote: > I received and applied your patches. I had to compile with ACPI > disabled because 3.3-rc2 now reports a resource conflict between the > WDAT structure (that we report for Microsoft Windows watchdog timer > support) and the TCO watchdog portion of lpc_ich: > > ACPI Warning: 0x00000460-0x0000047f SystemIO conflicts with > Region \PMIO 1 (20120111/utaddress-251) > ACPI: If an ACPI driver is available for this device, you should use > it instead of the native driver > lpc_ich: probe of 0000:00:1f.0 failed with error -16 > > We may have to submit a driver in the future to utilize the WDAT > ACPI table, but that's another topic. > > Do you think it's worth modifying lcp_ich to register all of the > resources that it can and only populate the mfd_cells that have > all of their required resources? That would prevent the entire > driver from bombing out in situations like this. I can't imagine > our BIOS is the only one implementing the WDAT table.
Yes, definitely. One subdevice being unavailable shouldn't have any impact on other subdevices. The lpc_sch driver suffers from the same issue, I had sent a patch one 10 months ago but it was never applied. I'll update it and resend it.
To mention another ACPI resource conflict that can happen, I see the following on my Asus Z8NA-D6:
ACPI Warning: 0x0000000000000500-0x000000000000053f SystemIO conflicts with Region \_SI_.LEDR 1 (20120111/utaddress-251) ACPI: If an ACPI driver is available for this device, you should use it instead of the native driver i801_gpio: probe of 0000:00:1f.0 failed with error -16
OperationRegion (LEDR, SystemIO, 0x051A, One) Field (LEDR, ByteAcc, NoLock, Preserve) { LEDY, 8 }
This is with my own GPIO driver, no MFD involved, so that's a different problem but your driver will likely show the same. This might mean that we have to fine-tune which I/O ports to request. In my case ACPI wants to access only the "GPIO Blink Enable" register, which neither my driver nor yours uses, so the conflict could be avoided.
> Anyway, after compiling without ACPI the lpc_ich driver registered > as expected and the gpio-ich and iTCO_wdt drivers detected and > configured their associated resources. I have verified that the > watchdog timer still works as expected. I need to track down some > other hardware to properly test the GPIO.
Note that for testing purpose only, it can be more convenient to boot with acpi_enforce_resources=lax rather than rebuilding the kernel without ACPI support.
-- Jean Delvare
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