On Thu, Jun 04, 2020 at 11:30:37PM +0200, Michael Walle wrote: > 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.
> --- > 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. Yeah, I'm not sure it's right thing to do, but let maintainers and more experienced in topic developers to speak up. -- With Best Regards, Andy Shevchenko