Commit cdfee5623290 ("driver core: initialize a default DMA mask for
platform device") initialize the DMA of a platform device. But if the
parent doesn't have a dma_mask set, for example if it's an I2C device,
the dma_mask of the child platform device will be set to zero again.
Which leads to many "DMA mask not set" warnings, if the MFD cell has the
of_compatible property set.[ 1.877937] sl28cpld-pwm sl28cpld-pwm: DMA mask not set [ 1.883282] sl28cpld-pwm sl28cpld-pwm.0: DMA mask not set [ 1.888795] sl28cpld-gpio sl28cpld-gpio: DMA mask not set Thus don't overwrite the dma_mask of the children. Instead set the dma_mask of the platform device. Signed-off-by: Michael Walle <mich...@walle.cc> Suggested-by: Robin Murphy <robin.mur...@arm.com> --- Former discussion was here: https://lore.kernel.org/lkml/20200423174543.17161-3-mich...@walle.cc/ Because my MFD driver now uses of_platform_populate() it doesn't trigger this anymore. But it may be useful for others, e.g. if I'm not mistaken it should apply to the mt6360 sub devices. Thus I'm submitting this patch seperately. drivers/mfd/mfd-core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index f5a73af60dd4..e735565969b3 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -138,7 +138,7 @@ static int mfd_add_device(struct device *parent, int id, pdev->dev.parent = parent; pdev->dev.type = &mfd_dev_type; - pdev->dev.dma_mask = parent->dma_mask; + pdev->platform_dma_mask = parent->dma_mask ? *parent->dma_mask : 0; pdev->dev.dma_parms = parent->dma_parms; pdev->dev.coherent_dma_mask = parent->coherent_dma_mask; -- 2.20.1
