Messages in this thread | | | Date | Fri, 18 Nov 2022 11:06:49 +0000 | Subject | Re: [PATCH] i2c: tegra: Set ACPI node as primary fwnode | From | Jon Hunter <> |
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On 18/11/2022 10:18, Thierry Reding wrote: > On Fri, Nov 18, 2022 at 09:38:52AM +0000, Jon Hunter wrote: >> >> On 17/11/2022 10:04, Akhil R wrote: >>> Set ACPI node as the primary fwnode of I2C adapter to allow >>> enumeration of child devices from the ACPI table >>> >>> Signed-off-by: Zubair Waheed <zwaheed@nvidia.com> >>> Signed-off-by: Akhil R <akhilrajeev@nvidia.com> >>> --- >>> drivers/i2c/busses/i2c-tegra.c | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c >>> index 954022c04cc4..69c9ae161bbe 100644 >>> --- a/drivers/i2c/busses/i2c-tegra.c >>> +++ b/drivers/i2c/busses/i2c-tegra.c >>> @@ -1826,6 +1826,7 @@ static int tegra_i2c_probe(struct platform_device *pdev) >>> i2c_dev->adapter.class = I2C_CLASS_DEPRECATED; >>> i2c_dev->adapter.algo = &tegra_i2c_algo; >>> i2c_dev->adapter.nr = pdev->id; >>> + ACPI_COMPANION_SET(&i2c_dev->adapter.dev, ACPI_COMPANION(&pdev->dev)); >>> if (i2c_dev->hw->supports_bus_clear) >>> i2c_dev->adapter.bus_recovery_info = &tegra_i2c_recovery_info; >> >> >> Do we always want to set as the primary fwnode even when booting with >> device-tree? I some other drivers do, but I also see some others ... >> >> if (has_acpi_companion(dev)) >> ACPI_COMPANION_SET(&i2c_dev->adapter.dev, >> ACPI_COMPANION(&pdev->dev)); >> >> It would be nice to know why it is OK to always do this even for device-tree >> because it is not clear to me. > > ACPI_COMPANION() returns NULL if there is no ACPI companion, which will > cause ACPI_COMPANION_SET() to set the primary fwnode to NULL. If I read > the code for set_primary_fwnode() correctly, that's essentially a no-op > for DT devices.
Yes it does, but doesn't it is not clear to me if it is a good idea to pass NULL to set_primary_fwnode(). It does seem to handle this but my biggest gripe is the lack of explanation in the commit message why this is OK.
Jon
-- nvpublic
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