Re: [PATCH v2] Revert "pinctrl: freescale: imx: Use 'devm_of_iomap()' to avoid a resource leak in case of error in 'imx_pinctrl_probe()'"

[Andy Shevchenko <andy.shevchenko@gmail.com>]

On Tue, Jun 16, 2020 at 5:54 AM Aisheng Dong <aisheng.dong@nxp.com> wrote:

> Could you help apply this patch as it blocked MX7D booting for a while?

> > This reverts commit ba403242615c2c99e27af7984b1650771a2cc2c9.
> >
> > After commit 26d8cde5260b ("pinctrl: freescale: imx: add shared input select
> > reg support"). i.MX7D has two iomux controllers iomuxc and iomuxc-lpsr which
> > share select_input register for daisy chain settings.
> > If use 'devm_of_iomap()', when probe the iomuxc-lpsr, will call
> > devm_request_mem_region() for the region <0x30330000-0x3033ffff> for the
> > first time. Then, next time when probe the iomuxc, API
> > devm_platform_ioremap_resource() will also use the API
> > devm_request_mem_region() for the share region <0x30330000-0x3033ffff>
> > again, then cause issue, log like below:
> >
> > [    0.179561] imx7d-pinctrl 302c0000.iomuxc-lpsr: initialized IMX pinctrl
> > driver
> > [    0.191742] imx7d-pinctrl 30330000.pinctrl: can't request region for
> > resource [mem 0x30330000-0x3033ffff]
> > [    0.191842] imx7d-pinctrl: probe of 30330000.pinctrl failed with error -16

It means that shared support took a wrong approach. If something has
shared resources, another schema should be used, something like MFD
(parent device which keeps only shared resources). Easiest way is to
switch to the regmap API.

P.S. The revert is okay as a quick fix but... see above.

-- 
With Best Regards,
Andy Shevchenko