Re: [PATCH 4/5] pinctrl: rza1: Fix selector use for groups and functions

From: jacopo mondi
Date: Tue Jun 19 2018 - 00:16:45 EST


Hi Tony,
thanks for doing this!

I cannot find the original bug report in linux-gpio, so I'll comment
on this single patch only.

On Fri, Jun 15, 2018 at 04:11:40AM -0700, Tony Lindgren wrote:
> We must use a mutex around the generic_add functions and save the
> function and group selector in case we need to remove them. Otherwise
> the selector use will be racy for deferred probe at least.
>
> Fixes: 5a49b644b307 ("pinctrl: Renesas RZ/A1 pin and gpio controller")
> Reported-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
> Cc: Haojian Zhuang <haojian.zhuang@xxxxxxxxxx>
> Cc: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> Cc: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
> Cc: Sean Wang <sean.wang@xxxxxxxxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> ---
> drivers/pinctrl/pinctrl-rza1.c | 25 +++++++++++++------------
> 1 file changed, 13 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/pinctrl/pinctrl-rza1.c b/drivers/pinctrl/pinctrl-rza1.c
> --- a/drivers/pinctrl/pinctrl-rza1.c
> +++ b/drivers/pinctrl/pinctrl-rza1.c
> @@ -1005,7 +1005,7 @@ static int rza1_dt_node_to_map(struct pinctrl_dev *pctldev,
> struct device_node *child;
> const char *grpname;
> const char **fngrps;
> - int ret, npins;
> + int ret, npins, gsel, fsel;

Nit: can you move this 3 lines up to keep the variable declarations in reverse
xmas tree order? or if you prefer declare one variable per line...

With this minor comment fixed:
Acked-by: Jacopo Mondi <jacopo@xxxxxxxxxx>

Thanks
j

>
> npins = rza1_dt_node_pin_count(np);
> if (npins < 0) {
> @@ -1055,18 +1055,19 @@ static int rza1_dt_node_to_map(struct pinctrl_dev *pctldev,
> fngrps[0] = grpname;
>
> mutex_lock(&rza1_pctl->mutex);
> - ret = pinctrl_generic_add_group(pctldev, grpname, grpins, npins,
> - NULL);
> - if (ret) {
> + gsel = pinctrl_generic_add_group(pctldev, grpname, grpins, npins,
> + NULL);
> + if (gsel < 0) {
> mutex_unlock(&rza1_pctl->mutex);
> - return ret;
> + return gsel;
> }
>
> - ret = pinmux_generic_add_function(pctldev, grpname, fngrps, 1,
> - mux_confs);
> - if (ret)
> + fsel = pinmux_generic_add_function(pctldev, grpname, fngrps, 1,
> + mux_confs);
> + if (fsel < 0) {
> + ret = fsel;
> goto remove_group;
> - mutex_unlock(&rza1_pctl->mutex);
> + }
>
> dev_info(rza1_pctl->dev, "Parsed function and group %s with %d pins\n",
> grpname, npins);
> @@ -1083,15 +1084,15 @@ static int rza1_dt_node_to_map(struct pinctrl_dev *pctldev,
> (*map)->data.mux.group = np->name;
> (*map)->data.mux.function = np->name;
> *num_maps = 1;
> + mutex_unlock(&rza1_pctl->mutex);
>
> return 0;
>
> remove_function:
> - mutex_lock(&rza1_pctl->mutex);
> - pinmux_generic_remove_last_function(pctldev);
> + pinmux_generic_remove_function(pctldev, fsel);
>
> remove_group:
> - pinctrl_generic_remove_last_group(pctldev);
> + pinctrl_generic_remove_group(pctldev, gsel);
> mutex_unlock(&rza1_pctl->mutex);
>
> dev_info(rza1_pctl->dev, "Unable to parse function and group %s\n",
> --
> 2.17.1

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