On Tue, Jun 16, 2020 at 10:31:54AM +0200, Linus Walleij wrote:
> On Mon, Jun 8, 2020 at 2:51 PM Drew Fustini <drew@xxxxxxxxxxxxxxx> wrote:
>
> > This patch causes pcs_parse_pinconf() to return -ENOTSUPP when no
> > pinctrl_map is added. The current behavior is to return 0 when
> > !PCS_HAS_PINCONF or !nconfs. Thus pcs_parse_one_pinctrl_entry()
> > incorrectly assumes that a map was added and sets num_maps = 2.
> >
> > Analysis:
> > =========
> > The function pcs_parse_one_pinctrl_entry() calls pcs_parse_pinconf()
> > if PCS_HAS_PINCONF is enabled. The function pcs_parse_pinconf()
> > returns 0 to indicate there was no error and num_maps is then set to 2:
> >
> > 980 static int pcs_parse_one_pinctrl_entry(struct pcs_device *pcs,
> > 981 struct device_node *np,
> > 982 struct pinctrl_map **map,
> > 983 unsigned *num_maps,
> > 984 const char **pgnames)
> > 985 {
> > <snip>
> > 1053 (*map)->type = PIN_MAP_TYPE_MUX_GROUP;
> > 1054 (*map)->data.mux.group = np->name;
> > 1055 (*map)->data.mux.function = np->name;
> > 1056
> > 1057 if (PCS_HAS_PINCONF && function) {
> > 1058 res = pcs_parse_pinconf(pcs, np, function, map);
> > 1059 if (res)
> > 1060 goto free_pingroups;
> > 1061 *num_maps = 2;
> > 1062 } else {
> > 1063 *num_maps = 1;
> > 1064 }
> >
> > However, pcs_parse_pinconf() will also return 0 if !PCS_HAS_PINCONF or
> > !nconfs. I believe these conditions should indicate that no map was
> > added by returning -ENOTSUPP. Otherwise pcs_parse_one_pinctrl_entry()
> > will set num_maps = 2 even though no maps were successfully added, as
> > it does not reach "m++" on line 940:
> >
> > 895 static int pcs_parse_pinconf(struct pcs_device *pcs, struct device_node *np,
> > 896 struct pcs_function *func,
> > 897 struct pinctrl_map **map)
> > 898
> > 899 {
> > 900 struct pinctrl_map *m = *map;
> > <snip>
> > 917 /* If pinconf isn't supported, don't parse properties in below. */
> > 918 if (!PCS_HAS_PINCONF)
> > 919 return 0;
> > 920
> > 921 /* cacluate how much properties are supported in current node */
> > 922 for (i = 0; i < ARRAY_SIZE(prop2); i++) {
> > 923 if (of_find_property(np, prop2[i].name, NULL))
> > 924 nconfs++;
> > 925 }
> > 926 for (i = 0; i < ARRAY_SIZE(prop4); i++) {
> > 927 if (of_find_property(np, prop4[i].name, NULL))
> > 928 nconfs++;
> > 929 }
> > 930 if (!nconfs)
> > 919 return 0;
> > 932
> > 933 func->conf = devm_kcalloc(pcs->dev,
> > 934 nconfs, sizeof(struct pcs_conf_vals),
> > 935 GFP_KERNEL);
> > 936 if (!func->conf)
> > 937 return -ENOMEM;
> > 938 func->nconfs = nconfs;
> > 939 conf = &(func->conf[0]);
> > 940 m++;
> >
> > This situtation will cause a boot failure [0] on the BeagleBone Black
> > (AM3358) when am33xx_pinmux node in arch/arm/boot/dts/am33xx-l4.dtsi
> > has compatible = "pinconf-single" instead of "pinctrl-single".
> >
> > The patch fixes this issue by returning -ENOSUPP when !PCS_HAS_PINCONF
> > or !nconfs, so that pcs_parse_one_pinctrl_entry() will know that no
> > map was added.
> >
> > Logic is also added to pcs_parse_one_pinctrl_entry() to distinguish
> > between -ENOSUPP and other errors. In the case of -ENOSUPP, num_maps
> > is set to 1 as it is valid for pinconf to be enabled and a given pin
> > group to not any pinconf properties.
> >
> > [0] https://lore.kernel.org/linux-omap/20200529175544.GA3766151@x1/
> >
> > Fixes: 9dddb4df90d1 ("pinctrl: single: support generic pinconf")
> > Signed-off-by: Drew Fustini <drew@xxxxxxxxxxxxxxx>
>
> Patch applied as non-critical (for-next) fix.
>
> If there is no hurry let's merge it this way with lots of testing
> along the way.
>
> Yours,
> Linus Walleij
Thanks, I agree more testing is a good idea.
In particular, do you have a way to followup with Haojian Zhuang within
Linaro?
Haojian added the generic pinconf support back in 2013, so it would be
good to get his review.
Also, neither Tony or I have the Hikey hardware to test.
The most important to test would be those which include a .dtsi with
"pinconf-single" compatible. I do plan to add pinconf-single to the
AM3358 BeagleBone (which is what I am testing on), but the current
mainline users are:
arch/arm/boot/dts/hi3620.dtsi
|- arch/arm/boot/dts/hi3620-hi4511.dts
arch/arm/boot/dts/pxa3xx.dtsi
|- arch/arm/boot/dts/pxa300-raumfeld-common.dtsi
|- arch/arm/boot/dts/pxa300-raumfeld-connector.dts
arch/arm/boot/dts/pxa300-raumfeld-controller.dts
arch/arm/boot/dts/pxa300-raumfeld-speaker-l.dts
arch/arm/boot/dts/pxa300-raumfeld-speaker-m.dts
arch/arm/boot/dts/pxa300-raumfeld-speaker-one.dts
arch/arm/boot/dts/pxa300-raumfeld-speaker-s.dts
I am cc'ing Daniel Mack and Robert Jarzmi as they are listed as
maintainers for the pxa300 related dts files.
Those platforms using compatible = "pinctrl-single" should not be
effected by this patch:
arch/arm/boot/dts/am33xx-l4.dtsi (I have changed to pinconf for test)
arch/arm/boot/dts/da850.dtsi
arch/arm/boot/dts/dm814x.dtsi
arch/arm/boot/dts/dm816x.dtsi
arch/arm/boot/dts/hi3620.dtsi
arch/arm/boot/dts/keystone-k2g.dtsi
arch/arm/boot/dts/keystone-k2l.dtsi
arch/arm/boot/dts/omap3-gta04.dtsi
Thanks,
Drew
