Re: [PATCH 08/17] clk: imx: convert to devm_platform_ioremap_resource

[Frank Lee <tiny.windzz@gmail.com>]

On Tue, Dec 10, 2019 at 4:44 AM Leonard Crestez <leonard.crestez@nxp.com> wrote:
>
> On 09.12.2019 21:58, Yangtao Li wrote:
> > Use devm_platform_ioremap_resource() to simplify code.
> >
> > Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
> > ---
> >   drivers/clk/imx/clk-imx8qxp-lpcg.c | 6 +-----
> >   1 file changed, 1 insertion(+), 5 deletions(-)
> >
> > diff --git a/drivers/clk/imx/clk-imx8qxp-lpcg.c b/drivers/clk/imx/clk-imx8qxp-lpcg.c
> > index c0aff7ca6374..10ae712447c6 100644
> > --- a/drivers/clk/imx/clk-imx8qxp-lpcg.c
> > +++ b/drivers/clk/imx/clk-imx8qxp-lpcg.c
> > @@ -164,7 +164,6 @@ static int imx8qxp_lpcg_clk_probe(struct platform_device *pdev)
> >       struct clk_hw_onecell_data *clk_data;
> >       const struct imx8qxp_ss_lpcg *ss_lpcg;
> >       const struct imx8qxp_lpcg_data *lpcg;
> > -     struct resource *res;
> >       struct clk_hw **clks;
> >       void __iomem *base;
> >       int i;
> > @@ -173,10 +172,7 @@ static int imx8qxp_lpcg_clk_probe(struct platform_device *pdev)
> >       if (!ss_lpcg)
> >               return -ENODEV;
> >
> > -     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > -     if (!res)
> > -             return -EINVAL;
> > -     base = devm_ioremap(dev, res->start, resource_size(res));
> > +     base = devm_platform_ioremap_resource(pdev, 0);
> >       if (!base)
> >               return -ENOMEM;
>
> This breaks imx8qxp-mek boot by causing most peripherals (like uart) to
> fail to probe.
>
> The old and new paths are not equivalent: devm_platform_ioremap_resource
> calls devm_ioremap_resource which differs from devm_ioremap by also
> calling devm_request_mem_region.
>
> This prevents other mappings in the area and imx8qxp-lpcg nodes map
> whole hardware "subsystems" and overlap most peripherals. For example:
>
>                   adma_lpcg: clock-controller@59000000 {
>                           compatible = "fsl,imx8qxp-lpcg-adma";
>                           reg = <0x59000000 0x2000000>;
>                           #clock-cells = <1>;
>                 };

It's a bit surprising that the clock driver does such a large mapping.

So, it is best to check the dts reg configuration of the driver.


Yours,
Yangtao

>
>                  adma_lpuart0: serial@5a060000 {
>                         reg = <0x5a060000 0x1000>;
>                         ...
>                 };
>
> I don't know if this issue affects any other platforms (imx8 lpcg
> bindings are unusual) but if you found this with an automated tool
> perhaps it should be adjusted?
>
> By my count it's the 4th time this incorrect cleanup was posted.
>
> Previously: https://lkml.org/lkml/2019/12/4/487
>
> --
> Regards,
> Leonard