Messages in this thread | | | Date | Tue, 25 Feb 2020 16:35:45 +0200 | From | Andy Shevchenko <> | Subject | Re: [PATCH 3/3] i2c: i801: Do not add ICH_RES_IO_SMI if PMC device is not present |
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On Tue, Feb 25, 2020 at 03:38:02PM +0300, Mika Westerberg wrote: > 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. > > Fix this by checking that the PMC device is there and only then populate > the iTCO_wdt ICH_RES_IO_SMI resource. Since the resource is now optional > the iTCO_wdt driver should continue to work on recent systems without it.
...
> return platform_device_register_resndata(&pci_dev->dev, "iTCO_wdt", -1, > - tco_res, 3, &spt_tco_platform_data, > + tco_res, nres + 1, &spt_tco_platform_data, > sizeof(spt_tco_platform_data));
Perhaps use the same pattern as below, i.e.
nres++; return ...(..., nres, ...);
?
...
> return platform_device_register_resndata(&pci_dev->dev, "iTCO_wdt", -1, > - tco_res, 2, &cnl_tco_platform_data, > + tco_res, nres, &cnl_tco_platform_data, > sizeof(cnl_tco_platform_data));
Ditto.
...
> + nres++;
-- With Best Regards, Andy Shevchenko
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