From: Mika Westerberg mika.westerberg@linux.intel.com
commit 04bbb97d1b732b2d197f103c5818f5c214a4cf81 upstream.
Martin noticed that nct6775 driver does not load properly on his system in v5.4+ kernels. The issue was bisected to commit b84398d6d7f9 ("i2c: i801: Use iTCO version 6 in Cannon Lake PCH and beyond") but it is likely not the culprit because the faulty code has been in the driver already since commit 9424693035a5 ("i2c: i801: Create iTCO device on newer Intel PCHs"). So more likely some commit that added PCI IDs of recent chipsets made the driver to create the iTCO_wdt device on Martins system.
The issue was debugged to be PCI configuration access to the PMC device that is not present. This returns all 1's when read and this caused the iTCO_wdt driver to accidentally request resourses used by nct6775.
It turns out that the SMI resource is only required for some ancient systems, not the ones supported by this driver. For this reason do not populate the SMI resource at all and drop all the related code. The driver now always populates the main I/O resource and only in case of SPT (Intel Sunrisepoint) compatible devices it adds another resource for the NO_REBOOT bit. These two resources are of different types so platform_get_resource() used by the iTCO_wdt driver continues to find the both resources at index 0.
Link: https://lore.kernel.org/linux-hwmon/CAM1AHpQ4196tyD=HhBu-2donSsuogabkfP03v1Y... Fixes: 9424693035a5 ("i2c: i801: Create iTCO device on newer Intel PCHs") [wsa: complete fix needs all of http://patchwork.ozlabs.org/project/linux-i2c/list/?series=160959&state=...] Reported-by: Martin Volf martin.volf.42@gmail.com Signed-off-by: Mika Westerberg mika.westerberg@linux.intel.com Reviewed-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Wolfram Sang wsa@the-dreams.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/i2c/busses/i2c-i801.c | 45 +++++++++++------------------------------- 1 file changed, 12 insertions(+), 33 deletions(-)
--- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -129,11 +129,6 @@ #define TCOBASE 0x050 #define TCOCTL 0x054
-#define ACPIBASE 0x040 -#define ACPIBASE_SMI_OFF 0x030 -#define ACPICTRL 0x044 -#define ACPICTRL_EN 0x080 - #define SBREG_BAR 0x10 #define SBREG_SMBCTRL 0xc6000c #define SBREG_SMBCTRL_DNV 0xcf000c @@ -1544,7 +1539,7 @@ i801_add_tco_spt(struct i801_priv *priv, pci_bus_write_config_byte(pci_dev->bus, devfn, 0xe1, hidden); spin_unlock(&p2sb_spinlock);
- res = &tco_res[ICH_RES_MEM_OFF]; + res = &tco_res[1]; if (pci_dev->device == PCI_DEVICE_ID_INTEL_DNV_SMBUS) res->start = (resource_size_t)base64_addr + SBREG_SMBCTRL_DNV; else @@ -1554,7 +1549,7 @@ i801_add_tco_spt(struct i801_priv *priv, res->flags = IORESOURCE_MEM;
return platform_device_register_resndata(&pci_dev->dev, "iTCO_wdt", -1, - tco_res, 3, &spt_tco_platform_data, + tco_res, 2, &spt_tco_platform_data, sizeof(spt_tco_platform_data)); }
@@ -1567,17 +1562,16 @@ static struct platform_device * i801_add_tco_cnl(struct i801_priv *priv, struct pci_dev *pci_dev, struct resource *tco_res) { - return platform_device_register_resndata(&pci_dev->dev, "iTCO_wdt", -1, - tco_res, 2, &cnl_tco_platform_data, - sizeof(cnl_tco_platform_data)); + return platform_device_register_resndata(&pci_dev->dev, + "iTCO_wdt", -1, tco_res, 1, &cnl_tco_platform_data, + sizeof(cnl_tco_platform_data)); }
static void i801_add_tco(struct i801_priv *priv) { - u32 base_addr, tco_base, tco_ctl, ctrl_val; struct pci_dev *pci_dev = priv->pci_dev; - struct resource tco_res[3], *res; - unsigned int devfn; + struct resource tco_res[2], *res; + u32 tco_base, tco_ctl;
/* If we have ACPI based watchdog use that instead */ if (acpi_has_watchdog()) @@ -1592,30 +1586,15 @@ static void i801_add_tco(struct i801_pri return;
memset(tco_res, 0, sizeof(tco_res)); - - res = &tco_res[ICH_RES_IO_TCO]; - res->start = tco_base & ~1; - res->end = res->start + 32 - 1; - res->flags = IORESOURCE_IO; - /* - * Power Management registers. + * Always populate the main iTCO IO resource here. The second entry + * for NO_REBOOT MMIO is filled by the SPT specific function. */ - devfn = PCI_DEVFN(PCI_SLOT(pci_dev->devfn), 2); - pci_bus_read_config_dword(pci_dev->bus, devfn, ACPIBASE, &base_addr); - - res = &tco_res[ICH_RES_IO_SMI]; - res->start = (base_addr & ~1) + ACPIBASE_SMI_OFF; - res->end = res->start + 3; + res = &tco_res[0]; + res->start = tco_base & ~1; + res->end = res->start + 32 - 1; res->flags = IORESOURCE_IO;
- /* - * Enable the ACPI I/O space. - */ - pci_bus_read_config_dword(pci_dev->bus, devfn, ACPICTRL, &ctrl_val); - ctrl_val |= ACPICTRL_EN; - pci_bus_write_config_dword(pci_dev->bus, devfn, ACPICTRL, ctrl_val); - if (priv->features & FEATURE_TCO_CNL) priv->tco_pdev = i801_add_tco_cnl(priv, pci_dev, tco_res); else