lkml.org 
[lkml]   [2020]   [Jun]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] mfd: mfd-core: Don't overwrite the dma_mask of the child device
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-michael@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


\
 
 \ /
  Last update: 2020-06-05 15:17    [W:0.518 / U:0.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site