> On 10/24/18 3:11 AM, Arnd Bergmann wrote:
>
> On Wed, Oct 17, 2018 at 11:30 PM Al Cooper <alcooperx@gmail.com> wrote:
>
> Add support for Broadcom STB SoC's to the ohci platform driver.
>
> Signed-off-by: Al Cooper <alcooperx@gmail.com>
> ---
>  drivers/usb/host/ohci-platform.c | 35 +++++++++++++++++++++++++++++------
>  include/linux/usb/ohci_pdriver.h |  1 +
>  2 files changed, 30 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/host/ohci-platform.c
b/drivers/usb/host/ohci-platform.c
> index 65a1c3fdc88c..363d6fa676a5 100644
> --- a/drivers/usb/host/ohci-platform.c
> +++ b/drivers/usb/host/ohci-platform.c
> @@ -22,6 +22,7 @@
>  #include <linux/module.h>
>  #include <linux/err.h>
>  #include <linux/of.h>
> +#include <linux/of_device.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/reset.h>
> @@ -99,12 +100,24 @@ static int ohci_platform_probe(struct
platform_device *dev)
>         if (usb_disabled())
>                 return -ENODEV;
>
> -       /*
> -        * Use reasonable defaults so platforms don't have to provide
these
> -        * with DT probing on ARM.
> -        */
> -       if (!pdata)
> -               pdata = &ohci_platform_defaults;
> +       if (!pdata) {
> +               const struct usb_ohci_pdata *match_pdata;
> +
> +               match_pdata = of_device_get_match_data(&dev->dev);
> +               if (match_pdata) {
> +                       pdata = devm_kzalloc(&dev->dev, sizeof(*pdata),
> +                                            GFP_KERNEL);
> +                       if (!pdata)
> +                               return -ENOMEM;
> +                       *pdata = *match_pdata;
>
> It looks like you copy the const pdata to get a non-const version.
> Have you tried
> propagating the 'const' modifier so that users can rely on that here?

The problem is that the const pdata from of_device_get_match() needs to be
saved in device->platform_data which is not a const pointer (and can't be
changed). How can I propagate the "const" to solve the problem?

>
> +               } else {
> +                       /*
> +                        * Use reasonable defaults so platforms don't have
> +                        * to provide these with DT probing on ARM.
> +                        */
> +                       pdata = &ohci_platform_defaults;
> +               }
> +       }
>
> That would also allow you to unify it with the else path by listing
> the ohci_platform_defaults
> in the id table for all other compatible strings.
>
>        Arnd