Re: [RFC PATCH 2/2] hwmon: (f71805f): Use request_region() in f71805f_init()

From: Guenter Roeck
Date: Thu Mar 14 2019 - 13:05:41 EST


On Fri, Mar 15, 2019 at 12:55:16AM +0800, John Garry wrote:
> Currently the driver does not call request_region() prior to
> accessing IO port regions in f71805f_init(), so add it.
>
> Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
> ---
> drivers/hwmon/f71805f.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hwmon/f71805f.c b/drivers/hwmon/f71805f.c
> index 73c681162653..910082c7f184 100644
> --- a/drivers/hwmon/f71805f.c
> +++ b/drivers/hwmon/f71805f.c
> @@ -1617,10 +1617,21 @@ static int __init f71805f_init(void)
> int err;
> unsigned short address;
> struct f71805f_sio_data sio_data;
> + struct resource *res;
> + size_t size = 0x4e - 0x2e + SIO_REG_ADDR + 4;
> +
> + /* Request the whole 0x2e - 0x4e region */
> + res = request_region(0x2e, size, "f71805f");

request_muxed_region() would be a better choice here since it doesn't
bail out immediately if the region is temporarily busy.

Thanks,
Guenter

> + if (!res)
> + return -EBUSY;
>
> if (f71805f_find(0x2e, &address, &sio_data)
> - && f71805f_find(0x4e, &address, &sio_data))
> + && f71805f_find(0x4e, &address, &sio_data)) {
> + release_region(0x2e, size);
> return -ENODEV;
> + }
> +
> + release_region(0x2e, size);
>
> err = platform_driver_register(&f71805f_driver);
> if (err)
> --
> 2.17.1
>