Hi again,
Sorry, Too early in the morning and I misunderstood the problem :-)
On Sun, Dec 30, 2018 at 8:24 AM Sergio Paracuellos
<sergio.paracuellos@xxxxxxxxx> wrote:
>
> Hi Neil,
>
> On Sun, Dec 30, 2018 at 4:58 AM NeilBrown <neil@xxxxxxxxxx> wrote:
> >
> > On Thu, Jun 07 2018, Sergio Paracuellos wrote:
> >
> > > Using 'function' and 'groups' bindings in the device tree give the
> > > posibility of refactor 'rt2880_pinctrl_dt_node_to_map' and simplify
> > > it a lot. Make use of the 'of_property_count_strings' function to get
> > > number of groups for the node and iterate over the groups using
> > > 'of_property_for_each_string' calling 'pinctrl_utils_add_map_mux'
> > > function which is the same of the custom function in this driver code
> > > 'rt2880_pinctrl_dt_subnode_to_map' which is not needed anymore.
> > >
> > > Signed-off-by: Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>
> >
> > Hi Sergio,
> > I've just noticed a problem with this code. The problem existed before
> > your patch - you didn't introduce it. But maybe you are more familiar
> > with the code and might like to fix it...
> >
> >
> > > ---
> > > drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c | 60 ++++++++-----------------
> > > 1 file changed, 18 insertions(+), 42 deletions(-)
> > >
> > > diff --git a/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c b/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c
> > > index 84494a1..8291ec0 100644
> > > --- a/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c
> > > +++ b/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c
> > ...
> >
> > > static int rt2880_pinctrl_dt_node_to_map(struct pinctrl_dev *pctrldev,
> > > struct device_node *np_config,
> > > struct pinctrl_map **map,
> > > unsigned int *num_maps)
> >
> > num_maps passed in ( from dt_to_map_one_config in
> > drivers/pinctrl/devicetree.c)
> > is the address of an uninitialised variable - has the value -1681671408 in one test
> > run.
> >
> >
> > > {
> > > struct rt2880_priv *p = pinctrl_dev_get_drvdata(pctrldev);
> > > + struct property *prop;
> > > + const char *function_name, *group_name;
> > > int ret;
> > > - int max_maps = 0;
> > > + int ngroups;
> > > unsigned int reserved_maps = 0;
> > > - struct pinctrl_map *tmp;
> > > - struct device_node *np;
> > >
> > > - for_each_child_of_node(np_config, np) {
> > > - int ret = of_property_count_strings(np, "ralink,group");
> > > -
> > > - if (ret >= 0)
> > > - max_maps += ret;
> > > + ngroups = of_property_count_strings(np_config, "groups");
> > > + if (!ngroups) {
> > > + dev_err(p->dev, "missing groups property in node %s\n",
> > > + np_config->name);
> > > + return -EINVAL;
> > > }
> > >
> > > - if (!max_maps)
> > > - return max_maps;
> > > -
> > > ret = pinctrl_utils_reserve_map(pctrldev, map, &reserved_maps,
> > > - num_maps, max_maps);
> > > + num_maps, ngroups);
> >
> > pinctrl_utils_reserve_map() expects *num_maps to be initialized here.
> > It does a memory allocation based on the value, and triggers a warning
> > for me:
> > if (unlikely(order >= MAX_ORDER)) {
> > WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
> > return NULL;
> > }
> >
> >
> > > if (ret) {
> > > dev_err(p->dev, "can't reserve map: %d\n", ret);
> > > return ret;
> > > }
> > >
> > > - tmp = *map;
> > > -
> > > - for_each_child_of_node(np_config, np)
> > > - rt2880_pinctrl_dt_subnode_to_map(pctrldev, np, &tmp);
> > > - *num_maps = max_maps;
> >
> > Previously *num_maps was initialised here - clearly too late. Now it
> > isn't initialised at all.
> > Do you know what value it should be set to?
So according the code before this PATCH the 'num_max' variable now
should be set to value of 'ngroups'.
So the following should fix the problem?
diff --git a/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c
b/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c
index aa98fbb17013..180f2afd7984 100644
--- a/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c
+++ b/drivers/staging/mt7621-pinctrl/pinctrl-rt2880.c
@@ -88,6 +88,7 @@ static int rt2880_pinctrl_dt_node_to_map(struct
pinctrl_dev *pctrldev,
for_each_node_with_property(np_config, "group")
ngroups++;
+ *num_maps = ngroups;
*map = NULL;
ret = pinctrl_utils_reserve_map(pctrldev, map, &reserved_maps,
num_maps, ngroups);
If so let me know and I'll send a real patch with all the fixes tags
and reported-by stuff.
Thanks,
Sergio Paracuellos
>
> In my staging tree the code is a bit different and the patch you are pointing
> out obviously is wrong because the value of 'num_maps' should be the number
> of bindings where the "group" property is set and not the "groups" one
> which is not
> a standard binding. So what I have is:
>
> static int rt2880_pinctrl_dt_node_to_map(struct pinctrl_dev *pctrldev,
> struct device_node *np_config,
> struct pinctrl_map **map,
> unsigned int *num_maps)
> {
> struct rt2880_priv *p = pinctrl_dev_get_drvdata(pctrldev);
> struct property *prop;
> const char *function_name, *group_name;
> int ret;
> int ngroups = 0;
> unsigned int reserved_maps = 0;
>
> for_each_node_with_property(np_config, "group")
> ngroups++;
>
> *map = NULL;
> ret = pinctrl_utils_reserve_map(pctrldev, map, &reserved_maps,
> num_maps, ngroups);
> if (ret) {
> dev_err(p->dev, "can't reserve map: %d\n", ret);
> return ret;
> }
>
> of_property_for_each_string(np_config, "group", prop, group_name) {
> ret = pinctrl_utils_add_map_mux(pctrldev, map, &reserved_maps,
> num_maps, group_name,
> function_name);
> if (ret) {
> dev_err(p->dev, "can't add map: %d\n", ret);
> return ret;
> }
> }
>
> return 0;
> }
>
> There was a fix, about the ngroups property to be initialized to zero
> so at least
> even if there is no bindings defined in the DT the value should be initialized.
>
> See:
> https://lkml.org/lkml/2018/11/11/115
>
> Am I missing something?
>
> >
> > Thanks,
> > NeilBrown
> >
>
> Hope this helps.
>
> Best regards,
> Sergio Paracuellos
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