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Drew Fustini 8bf3b460bf pinctrl-single: fix pcs_parse_pinconf() return value
[ Upstream commit f46fe79ff1 ]

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: 9dddb4df90 ("pinctrl: single: support generic pinconf")
Signed-off-by: Drew Fustini <drew@beagleboard.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20200608125143.GA2789203@x1
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-19 08:15:02 +02:00
arch powerpc/boot: Fix CONFIG_PPC_MPC52XX references 2020-08-19 08:15:00 +02:00
block block: release bip in a right way in error path 2020-07-16 08:17:23 +02:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: af_alg - fix use-after-free in af_alg_accept() due to bh_lock_sock() 2020-07-09 09:37:10 +02:00
Documentation iio: improve IIO_CONCENTRATION channel type description 2020-08-19 08:14:54 +02:00
drivers pinctrl-single: fix pcs_parse_pinconf() return value 2020-08-19 08:15:02 +02:00
firmware Fix built-in early-load Intel microcode alignment 2020-01-23 08:21:29 +01:00
fs ocfs2: fix unbalanced locking 2020-08-19 08:15:02 +02:00
include ipvs: allow connection reuse for unconfirmed conntrack 2020-08-19 08:14:56 +02:00
init printk: queue wake_up_klogd irq_work only if per-CPU areas are ready 2020-07-22 09:32:13 +02:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:18:40 +02:00
kernel sched: correct SD_flags returned by tl->sd_flags() 2020-08-19 08:14:47 +02:00
lib dyndbg: fix a BUG_ON in ddebug_describe_flags 2020-08-19 08:14:53 +02:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls 2020-08-19 08:14:52 +02:00
net ipvs: allow connection reuse for unconfirmed conntrack 2020-08-19 08:14:56 +02:00
samples samples: bpf: Fix build error 2020-06-03 08:19:31 +02:00
scripts scripts/gdb: fix lx-symbols 'gdb.error' while loading modules 2020-07-29 10:16:51 +02:00
security Smack: prevent underflow in smk_set_cipso() 2020-08-19 08:14:59 +02:00
sound ASoC: meson: axg-tdm-interface: fix link fmt setup 2020-08-19 08:15:01 +02:00
tools tools, build: Propagate build failures from tools/build/Makefile.build 2020-08-19 08:15:01 +02:00
usr initramfs: restore default compression behavior 2020-04-13 10:44:59 +02:00
virt KVM: arm64: Synchronize sysreg state on injecting an AArch32 exception 2020-06-22 09:05:09 +02:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS MAINTAINERS: Update drm/i915 bug filing URL 2020-02-28 16:38:49 +01:00
Makefile Linux 4.19.139 2020-08-11 15:32:36 +02:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
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the problems which may result by upgrading your kernel.