| Message ID | 20200531204147.GA664833@x1 |
|---|---|
| State | New |
| Headers | show |
| Series | pinctrl-single: fix pcs_parse_pinconf() return val | expand |
* Drew Fustini <drew@beagleboard.org> [200531 20:42]: > This patch causes pcs_parse_pinconf() to return an error 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. Looks OK to me, would be good to wait for Haojian to test this one. Regards, Tony
On Mon, Jun 01, 2020 at 09:18:51AM -0700, Tony Lindgren wrote: > * Drew Fustini <drew@beagleboard.org> [200531 20:42]: > > This patch causes pcs_parse_pinconf() to return an error 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. > > Looks OK to me, would be good to wait for Haojian to test this one. > > Regards, > > Tony Yes, I would like to get input as I don't have the other platforms using "pinconf,single": $ git grep 'compatible = "pinconf-single"' arch/ arch/arm/boot/dts/am33xx-l4.dtsi: compatible = "pinconf-single"; arch/arm/boot/dts/hi3620.dtsi: compatible = "pinconf-single"; arch/arm/boot/dts/pxa3xx.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/broadcom/stingray/stingray-pinctrl.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hi3798cv200.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hi6220.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hi6220.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hikey960-pinctrl.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hikey960-pinctrl.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hikey960-pinctrl.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hikey960-pinctrl.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hikey960-pinctrl.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hikey970-pinctrl.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hikey970-pinctrl.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hikey970-pinctrl.dtsi: compatible = "pinconf-single"; arch/arm64/boot/dts/hisilicon/hikey970-pinctrl.dtsi: compatible = "pinconf-single"; NOTE: the arch/arm/boot/dts/am33xx-l4.dtsi was patched by me from "pinctrl-single" to "pinconf-single. But, I think for upstream submission I would need to move that to one of the beaglebone specific dts files like am335x-bone-common.dtsi. I believe this pinctrl-single.c patch fixes a flaw in return logic and is useful regardless of whether beaglebone adopts "pinconf,single". However, I would very much like to get input from others in case my analysis is too narrow. Thanks, Drew
On 5/31/20 15:41, Drew Fustini wrote: > This patch causes pcs_parse_pinconf() to return an error 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 non-zero. 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. > > [0] https://lore.kernel.org/linux-omap/20200529175544.GA3766151@x1/ > Maybe add this Fixes tag here: Fixes: 9dddb4df90d1 ("pinctrl: single: support generic pinconf") -- Gustavo > Signed-off-by: Drew Fustini <drew@beagleboard.org> > --- > drivers/pinctrl/pinctrl-single.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c > index 1e0614daee9b..18a02cd0c701 100644 > --- a/drivers/pinctrl/pinctrl-single.c > +++ b/drivers/pinctrl/pinctrl-single.c > @@ -916,7 +916,7 @@ static int pcs_parse_pinconf(struct pcs_device *pcs, struct device_node *np, > > /* If pinconf isn't supported, don't parse properties in below. */ > if (!PCS_HAS_PINCONF) > - return 0; > + return -ENOTSUPP; /* do not return 0 as no map added */ > > /* cacluate how much properties are supported in current node */ > for (i = 0; i < ARRAY_SIZE(prop2); i++) { > @@ -928,7 +928,7 @@ static int pcs_parse_pinconf(struct pcs_device *pcs, struct device_node *np, > nconfs++; > } > if (!nconfs) > - return 0; > + return -ENOTSUPP; /* do not return 0 as no map added */ > > func->conf = devm_kcalloc(pcs->dev, > nconfs, sizeof(struct pcs_conf_vals), >
diff --git a/drivers/pinctrl/pinctrl-single.c b/drivers/pinctrl/pinctrl-single.c index 1e0614daee9b..18a02cd0c701 100644 --- a/drivers/pinctrl/pinctrl-single.c +++ b/drivers/pinctrl/pinctrl-single.c @@ -916,7 +916,7 @@ static int pcs_parse_pinconf(struct pcs_device *pcs, struct device_node *np, /* If pinconf isn't supported, don't parse properties in below. */ if (!PCS_HAS_PINCONF) - return 0; + return -ENOTSUPP; /* do not return 0 as no map added */ /* cacluate how much properties are supported in current node */ for (i = 0; i < ARRAY_SIZE(prop2); i++) { @@ -928,7 +928,7 @@ static int pcs_parse_pinconf(struct pcs_device *pcs, struct device_node *np, nconfs++; } if (!nconfs) - return 0; + return -ENOTSUPP; /* do not return 0 as no map added */ func->conf = devm_kcalloc(pcs->dev, nconfs, sizeof(struct pcs_conf_vals),
This patch causes pcs_parse_pinconf() to return an error 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 non-zero. 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. [0] https://lore.kernel.org/linux-omap/20200529175544.GA3766151@x1/ Signed-off-by: Drew Fustini <drew@beagleboard.org> --- drivers/pinctrl/pinctrl-single.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)