On Fri, 14 Jun 2019 15:40:59 -0700, "Alexander Ivanov" said:

(Adding likely knowledgeable  people to the recipients)

Jean,  Andy, Linus: The situation thus far:  Alexander has a system with this GPIO on it:

> lspci -vvvnns 1f.1
> 00:1f.1 Memory controller [0580]: Intel Corporation Device [8086:9d20] (rev 21)
>  Subsystem: Gigabyte Technology Co., Ltd Device [1458:1000]
>  Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
>  Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
>  Latency: 0
>  Region 0: Memory at 7d000000 (64-bit, non-prefetchable) [size=16M]

The obvious first thing to try was:

diff --git a/drivers/gpio/gpio-pch.c b/drivers/gpio/gpio-pch.c
index 1d99293096f2..19884b5b2a74 100644
--- a/drivers/gpio/gpio-pch.c
+++ b/drivers/gpio/gpio-pch.c
@@ -439,6 +439,7 @@ static SIMPLE_DEV_PM_OPS(pch_gpio_pm_ops, pch_gpio_suspend, pch_gpio_resume);

 static const struct pci_device_id pch_gpio_pcidev_id[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x8803) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x9d20) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8014) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8043) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_ROHM, 0x8803) },

and that died thusly when attempted to load:

[ 105.965846] pci 0000:00:1f.1: [8086:9d20] type 00 class 0x058000
[ 105.965928] pci 0000:00:1f.1: reg 0x10: [mem 0xfd000000-0xfdffffff 64bit]
[ 105.967084] pci 0000:00:1f.1: BAR 0: assigned [mem 0x7d000000-0x7dffffff 64bit]
[ 105.978037] pch_gpio 0000:00:1f.1: pch_gpio_probe : pci_iomap FAILED
[ 105.978194] pch_gpio 0000:00:1f.1: pch_gpio_probe Failed returns -12
[ 105.978317] pch_gpio: probe of 0000:00:1f.1 failed with error -12

So obviously an older kernel.  Not sure what release Alexander is on, but
a 'git log' against this week's linux-next tree didn't show anything that was
an obvious fix for a similar problem.

Any ideas?