[PATCH] staging: mt7621-pinctrl: fix pinmux warning at boot

[Sergio Paracuellos]

Hi Greg,

On Mon, Jan 14, 2019 at 6:36 AM Greg Ungerer <gerg at kernel.org> wrote:
>
> Fix unassigned "num_maps" when calling pinctrl_utils_reserve_map() in
> the satging mt7621-pinctrl driver. Although we do set an initial "map"
> pointer to NULL, there is no initialization of the "num_maps" argument.
>
> Uninitialized "num_maps" causes the following warning on boot on 5.0-rc1:
>
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 1 at mm/page_alloc.c:4511 __alloc_pages_nodemask+0x1d0/0xb70
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc1-00004-gf3cdc52549a2 #2
> Stack : 00000046 00000000 00000000 807e0000 87d1e580 8006fb04 8072da9c 0000000b
>         00000000 00000000 8072d2dc 87c3d894 80770000 00000001 87c3d828 588f41e8
>         00000000 00000000 80820000 00000000 00000000 807e76a6 00000047 00000000
>         2d316372 00000000 00000000 00000000 80770000 00000000 806eb6b8 00000009
>         0000119f 80770000 80700000 807016cc 00000010 00000001 00000000 807e0000
>         ...
> Call Trace:
> [<8000cfe0>] show_stack+0x94/0x12c
> [<8060dd7c>] dump_stack+0x8c/0xd0
> [<80028430>] __warn+0x10c/0x120
> [<80028554>] warn_slowpath_null+0x44/0x60
> [<800e27a8>] __alloc_pages_nodemask+0x1d0/0xb70
> [<800fe4a8>] kmalloc_order+0x20/0x54
> [<800fe858>] krealloc+0x7c/0x108
> [<802ec9c8>] pinctrl_utils_reserve_map+0x88/0x100
> [<80445f0c>] rt2880_pinctrl_dt_node_to_map+0xa0/0x18c
> [<802ede20>] pinctrl_dt_to_map+0x274/0x394
> [<802eb7cc>] create_pinctrl+0x80/0x478
> [<802ebd7c>] pinctrl_enable+0x20/0x148
> [<802ebed0>] pinctrl_register+0x2c/0x50
> [<80446514>] rt2880_pinmux_probe+0x51c/0x758
> [<80352d24>] platform_drv_probe+0x40/0x9c
> [<80350e48>] really_probe+0x1f0/0x35c
> [<8034ed74>] bus_for_each_drv+0x78/0xd0
> [<80350c10>] __device_attach+0xdc/0x11c
> [<8034ff04>] bus_probe_device+0xa0/0xbc
> [<8034c548>] device_add+0x3c8/0x618
> [<8043df90>] of_platform_device_create_pdata+0xac/0x120
> [<8043e1b4>] of_platform_bus_create+0x168/0x260
> [<8043e42c>] of_platform_populate+0x7c/0xec
> [<8079985c>] __dt_register_buses+0x70/0x90
> [<80798df0>] plat_of_setup+0x1c/0x34
> [<800015f4>] do_one_initcall+0x50/0x1ac
> [<80795e48>] kernel_init_freeable+0x184/0x26c
> [<8062bad4>] kernel_init+0x14/0x110
> [<80007198>] ret_from_kernel_thread+0x14/0x1c
> ---[ end trace d752c6e38e5b8de8 ]---
> rt2880-pinmux pinctrl: krealloc(map) failed
> rt2880-pinmux pinctrl: can't reserve map: -12
> rt2880-pinmux pinctrl: error claiming hogs: -12
> rt2880-pinmux pinctrl: could not claim hogs: -12
> rt2880-pinmux: probe of pinctrl failed with error -12
>
> Signed-off-by: Greg Ungerer <gerg at kernel.org>
> ---
>  drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c b/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c
> index aa98fbb17013..b007f905b24e 100644
> --- a/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c
> +++ b/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c
> @@ -89,6 +89,7 @@ static int rt2880_pinctrl_dt_node_to_map(struct pinctrl_dev *pctrldev,
>                 ngroups++;
>
>         *map = NULL;
> +       *num_maps = 0;
>         ret = pinctrl_utils_reserve_map(pctrldev, map, &reserved_maps,
>                                         num_maps, ngroups);
>         if (ret) {
> --
> 2.17.1
>

This warning has been fixed and patches applied to the staging tree
last week. Please see:

https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git/commit/?h=staging-testing&id=0ca1f90861b6d64386261096b42bfc81ce11948a
https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git/commit/?h=staging-testing&id=bd7c95d48854af2db899bc8b6966a0e9b9f5bf4e

Best regards,
    Sergio Paracuellos