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meson64: add GPIO shared-proxy/pinctrl cansleep series (upstream v3)
Two related upstream patches, grouped under one prefix + number, in meson64-7.1 and meson64-7.2: - general-gpio-shared-cansleep-0001-gpio-shared-proxy-always-mutex.patch: serialize the shared GPIO descriptor with a sleeping mutex; gpio_shared_proxy_set_unlocked() calls gpiod_set_value_cansleep() directly; the proxy gpiochip is always sleeping. - general-gpio-shared-cansleep-0002-pinctrl-meson-restore-non-sleeping-gpio.patch: restore meson gpio_chip.can_sleep = false (applies after 0001). meson64-7.2 shipped an earlier draft of these under separate filenames; this replaces it with the grouped versions. meson64-6.12/6.18 carry no shared-proxy driver and are unchanged.
1 parent 068ba63 commit b5dd29a

4 files changed

Lines changed: 292 additions & 96 deletions

patch/kernel/archive/meson64-7.1/general-gpio-shared-proxy-always-mutex.patch renamed to patch/kernel/archive/meson64-7.1/general-gpio-shared-cansleep-0001-gpio-shared-proxy-always-mutex.patch

Lines changed: 142 additions & 44 deletions
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
From e6d479eeaa03b9073304c0475dd72d781911b196 Mon Sep 17 00:00:00 2001
1+
From 770d943aac95c337f91280425f154846a9a41ef6 Mon Sep 17 00:00:00 2001
22
From: Viacheslav Bocharov <v@baodeep.com>
33
Date: Tue, 9 Jun 2026 16:37:20 +0300
44
Subject: [PATCH] gpio: shared-proxy: always serialize with a sleeping mutex
@@ -39,6 +39,14 @@ underlying GPIO through the cansleep value accessors: those are valid
3939
for both sleeping and non-sleeping chips, so value access keeps working
4040
on fast controllers, at the cost of no longer being atomic.
4141

42+
With every vote edge now driven through the cansleep value setter,
43+
gpio_shared_proxy_set_unlocked() no longer needs a per-call setter: drop
44+
its set_func callback and call gpiod_set_value_cansleep() directly. The
45+
shared direction_output path reaches it only once the line is already an
46+
output, so driving the value there is equivalent to re-issuing
47+
gpiod_direction_output(), without the redundant per-edge re-assertion of
48+
drive config and bias.
49+
4250
This is observable: consumers gating on gpiod_cansleep() take their
4351
sleeping branch on a proxied GPIO (mmc-pwrseq-emmc skips its
4452
emergency-restart reset handler; its normal reset is unaffected), and
@@ -59,39 +67,129 @@ Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
5967
Closes: https://lore.kernel.org/all/00107523-7737-4b92-a785-14ce4e93b8cb@samsung.com/
6068
Signed-off-by: Viacheslav Bocharov <v@baodeep.com>
6169
---
62-
drivers/gpio/gpio-shared-proxy.c | 43 +++++++-------------------------
63-
drivers/gpio/gpiolib-shared.c | 9 ++-----
64-
drivers/gpio/gpiolib-shared.h | 31 +++++++++--------------
65-
3 files changed, 23 insertions(+), 60 deletions(-)
70+
drivers/gpio/gpio-shared-proxy.c | 76 ++++++++++++--------------------
71+
drivers/gpio/gpiolib-shared.c | 9 +---
72+
drivers/gpio/gpiolib-shared.h | 28 +-----------
73+
3 files changed, 32 insertions(+), 81 deletions(-)
6674

6775
diff --git a/drivers/gpio/gpio-shared-proxy.c b/drivers/gpio/gpio-shared-proxy.c
68-
index 6941e4be6cf1..856e5b9d6163 100644
76+
index 6941e4be6cf1..10ca2ef77ef3 100644
6977
--- a/drivers/gpio/gpio-shared-proxy.c
7078
+++ b/drivers/gpio/gpio-shared-proxy.c
71-
@@ -109,7 +109,7 @@ static void gpio_shared_proxy_free(struct gpio_chip *gc, unsigned int offset)
79+
@@ -9,8 +9,10 @@
80+
#include <linux/err.h>
81+
#include <linux/gpio/consumer.h>
82+
#include <linux/gpio/driver.h>
83+
+#include <linux/lockdep.h>
84+
#include <linux/mod_devicetable.h>
85+
#include <linux/module.h>
86+
+#include <linux/mutex.h>
87+
#include <linux/string_choices.h>
88+
#include <linux/types.h>
89+
90+
@@ -24,15 +26,13 @@ struct gpio_shared_proxy_data {
91+
};
92+
93+
static int
94+
-gpio_shared_proxy_set_unlocked(struct gpio_shared_proxy_data *proxy,
95+
- int (*set_func)(struct gpio_desc *desc, int value),
96+
- int value)
97+
+gpio_shared_proxy_set_unlocked(struct gpio_shared_proxy_data *proxy, int value)
98+
{
99+
struct gpio_shared_desc *shared_desc = proxy->shared_desc;
100+
struct gpio_desc *desc = shared_desc->desc;
101+
int ret = 0;
102+
103+
- gpio_shared_lockdep_assert(shared_desc);
104+
+ lockdep_assert_held(&shared_desc->mutex);
105+
106+
if (value) {
107+
/* User wants to set value to high. */
108+
@@ -46,7 +46,7 @@ gpio_shared_proxy_set_unlocked(struct gpio_shared_proxy_data *proxy,
109+
* Current value is low, need to actually set value
110+
* to high.
111+
*/
112+
- ret = set_func(desc, 1);
113+
+ ret = gpiod_set_value_cansleep(desc, 1);
114+
if (ret)
115+
goto out;
116+
}
117+
@@ -65,7 +65,7 @@ gpio_shared_proxy_set_unlocked(struct gpio_shared_proxy_data *proxy,
118+
/* We previously voted for high. */
119+
if (shared_desc->highcnt == 1) {
120+
/* This is the last remaining vote for high, set value to low. */
121+
- ret = set_func(desc, 0);
122+
+ ret = gpiod_set_value_cansleep(desc, 0);
123+
if (ret)
124+
goto out;
125+
}
126+
@@ -89,7 +89,7 @@ static int gpio_shared_proxy_request(struct gpio_chip *gc, unsigned int offset)
127+
struct gpio_shared_proxy_data *proxy = gpiochip_get_data(gc);
128+
struct gpio_shared_desc *shared_desc = proxy->shared_desc;
129+
130+
- guard(gpio_shared_desc_lock)(shared_desc);
131+
+ guard(mutex)(&shared_desc->mutex);
132+
133+
proxy->shared_desc->usecnt++;
134+
135+
@@ -105,11 +105,10 @@ static void gpio_shared_proxy_free(struct gpio_chip *gc, unsigned int offset)
136+
struct gpio_shared_desc *shared_desc = proxy->shared_desc;
137+
int ret;
138+
139+
- guard(gpio_shared_desc_lock)(shared_desc);
140+
+ guard(mutex)(&shared_desc->mutex);
72141

73142
if (proxy->voted_high) {
74-
ret = gpio_shared_proxy_set_unlocked(proxy,
143+
- ret = gpio_shared_proxy_set_unlocked(proxy,
75144
- shared_desc->can_sleep ? gpiod_set_value_cansleep : gpiod_set_value, 0);
76-
+ gpiod_set_value_cansleep, 0);
145+
+ ret = gpio_shared_proxy_set_unlocked(proxy, 0);
77146
if (ret)
78147
dev_err(proxy->dev,
79148
"Failed to unset the shared GPIO value on release: %d\n", ret);
80-
@@ -222,13 +222,6 @@ static int gpio_shared_proxy_direction_output(struct gpio_chip *gc,
81-
return gpio_shared_proxy_set_unlocked(proxy, gpiod_direction_output, value);
82-
}
149+
@@ -129,7 +128,7 @@ static int gpio_shared_proxy_set_config(struct gpio_chip *gc,
150+
struct gpio_desc *desc = shared_desc->desc;
151+
int ret;
152+
153+
- guard(gpio_shared_desc_lock)(shared_desc);
154+
+ guard(mutex)(&shared_desc->mutex);
155+
156+
if (shared_desc->usecnt > 1) {
157+
if (shared_desc->cfg != cfg) {
158+
@@ -157,7 +156,7 @@ static int gpio_shared_proxy_direction_input(struct gpio_chip *gc,
159+
struct gpio_desc *desc = shared_desc->desc;
160+
int dir;
161+
162+
- guard(gpio_shared_desc_lock)(shared_desc);
163+
+ guard(mutex)(&shared_desc->mutex);
164+
165+
if (shared_desc->usecnt == 1) {
166+
dev_dbg(proxy->dev,
167+
@@ -187,7 +186,7 @@ static int gpio_shared_proxy_direction_output(struct gpio_chip *gc,
168+
struct gpio_desc *desc = shared_desc->desc;
169+
int ret, dir;
83170

171+
- guard(gpio_shared_desc_lock)(shared_desc);
172+
+ guard(mutex)(&shared_desc->mutex);
173+
174+
if (shared_desc->usecnt == 1) {
175+
dev_dbg(proxy->dev,
176+
@@ -219,14 +218,7 @@ static int gpio_shared_proxy_direction_output(struct gpio_chip *gc,
177+
return -EPERM;
178+
}
179+
180+
- return gpio_shared_proxy_set_unlocked(proxy, gpiod_direction_output, value);
181+
-}
182+
-
84183
-static int gpio_shared_proxy_get(struct gpio_chip *gc, unsigned int offset)
85184
-{
86185
- struct gpio_shared_proxy_data *proxy = gpiochip_get_data(gc);
87186
-
88187
- return gpiod_get_value(proxy->shared_desc->desc);
89-
-}
90-
-
188+
+ return gpio_shared_proxy_set_unlocked(proxy, value);
189+
}
190+
91191
static int gpio_shared_proxy_get_cansleep(struct gpio_chip *gc,
92-
unsigned int offset)
93-
{
94-
@@ -237,29 +230,15 @@ static int gpio_shared_proxy_get_cansleep(struct gpio_chip *gc,
192+
@@ -237,29 +229,14 @@ static int gpio_shared_proxy_get_cansleep(struct gpio_chip *gc,
95193
return gpiod_get_value_cansleep(proxy->shared_desc->desc);
96194
}
97195

@@ -118,19 +216,27 @@ index 6941e4be6cf1..856e5b9d6163 100644
118216
struct gpio_shared_proxy_data *proxy = gpiochip_get_data(gc);
119217

120218
- return gpio_shared_proxy_do_set(proxy, gpiod_set_value_cansleep, value);
121-
+ guard(gpio_shared_desc_lock)(proxy->shared_desc);
219+
+ guard(mutex)(&proxy->shared_desc->mutex);
122220
+
123-
+ return gpio_shared_proxy_set_unlocked(proxy, gpiod_set_value_cansleep,
124-
+ value);
221+
+ return gpio_shared_proxy_set_unlocked(proxy, value);
125222
}
126223

127224
static int gpio_shared_proxy_get_direction(struct gpio_chip *gc,
128-
@@ -302,20 +281,16 @@ static int gpio_shared_proxy_probe(struct auxiliary_device *adev,
225+
@@ -302,20 +279,25 @@ static int gpio_shared_proxy_probe(struct auxiliary_device *adev,
129226
gc->label = dev_name(dev);
130227
gc->parent = dev;
131228
gc->owner = THIS_MODULE;
132229
- gc->can_sleep = shared_desc->can_sleep;
133-
+ /* Always a sleeping gpiochip: see the lock comment in gpiolib-shared.h. */
230+
+ /*
231+
+ * Under the descriptor mutex the proxy may call
232+
+ * gpiod_set_config()/gpiod_direction_*(), which can reach pinctrl
233+
+ * paths that take a mutex (e.g. gpiod_set_config() ->
234+
+ * gpiochip_generic_config() -> pinctrl_gpio_set_config()), independent
235+
+ * of the underlying chip's can_sleep. So the descriptor lock must be a
236+
+ * mutex and the proxy gpiochip is therefore always sleeping; drive the
237+
+ * underlying GPIO through the cansleep value accessors, which are valid
238+
+ * for both sleeping and non-sleeping chips.
239+
+ */
134240
+ gc->can_sleep = true;
135241

136242
gc->request = gpio_shared_proxy_request;
@@ -178,18 +284,21 @@ index de72776fb154..495bd3d0ddf0 100644
178284
return shared_desc;
179285
}
180286
diff --git a/drivers/gpio/gpiolib-shared.h b/drivers/gpio/gpiolib-shared.h
181-
index 15e72a8dcdb1..5c725118b1af 100644
287+
index 15e72a8dcdb1..bbdc0ab7b647 100644
182288
--- a/drivers/gpio/gpiolib-shared.h
183289
+++ b/drivers/gpio/gpiolib-shared.h
184-
@@ -6,7 +6,6 @@
185-
#include <linux/cleanup.h>
186-
#include <linux/lockdep.h>
290+
@@ -3,10 +3,7 @@
291+
#ifndef __LINUX_GPIO_SHARED_H
292+
#define __LINUX_GPIO_SHARED_H
293+
294+
-#include <linux/cleanup.h>
295+
-#include <linux/lockdep.h>
187296
#include <linux/mutex.h>
188297
-#include <linux/spinlock.h>
189298

190299
struct gpio_device;
191300
struct gpio_desc;
192-
@@ -42,35 +41,29 @@ static inline int gpio_shared_add_proxy_lookup(struct device *consumer,
301+
@@ -42,35 +39,12 @@ static inline int gpio_shared_add_proxy_lookup(struct device *consumer,
193302

194303
struct gpio_shared_desc {
195304
struct gpio_desc *desc;
@@ -206,15 +315,7 @@ index 15e72a8dcdb1..5c725118b1af 100644
206315

207316
struct gpio_shared_desc *devm_gpiod_shared_get(struct device *dev);
208317

209-
+/*
210-
+ * Under this lock the proxy may call gpiod_set_config()/gpiod_direction_*(),
211-
+ * which can reach pinctrl paths that take a mutex (e.g. gpiod_set_config() ->
212-
+ * gpiochip_generic_config() -> pinctrl_gpio_set_config()), independent of the
213-
+ * underlying chip's can_sleep. A spinlock would run that sleeping call from
214-
+ * atomic context, so the descriptor lock must be a mutex and the proxy
215-
+ * gpiochip is therefore sleeping (can_sleep=true).
216-
+ */
217-
DEFINE_LOCK_GUARD_1(gpio_shared_desc_lock, struct gpio_shared_desc,
318+
-DEFINE_LOCK_GUARD_1(gpio_shared_desc_lock, struct gpio_shared_desc,
218319
- if (_T->lock->can_sleep)
219320
- mutex_lock(&_T->lock->mutex);
220321
- else
@@ -224,18 +325,15 @@ index 15e72a8dcdb1..5c725118b1af 100644
224325
- else
225326
- spin_unlock_irqrestore(&_T->lock->spinlock, _T->flags),
226327
- unsigned long flags)
227-
+ mutex_lock(&_T->lock->mutex),
228-
+ mutex_unlock(&_T->lock->mutex))
229-
230-
static inline void gpio_shared_lockdep_assert(struct gpio_shared_desc *shared_desc)
231-
{
328+
-
329+
-static inline void gpio_shared_lockdep_assert(struct gpio_shared_desc *shared_desc)
330+
-{
232331
- if (shared_desc->can_sleep)
233332
- lockdep_assert_held(&shared_desc->mutex);
234333
- else
235334
- lockdep_assert_held(&shared_desc->spinlock);
236-
+ lockdep_assert_held(&shared_desc->mutex);
237-
}
238-
335+
-}
336+
-
239337
#endif /* __LINUX_GPIO_SHARED_H */
240338
--
241339
2.54.0

patch/kernel/archive/meson64-7.1/general-pinctrl-meson-restore-non-sleeping-gpio.patch renamed to patch/kernel/archive/meson64-7.1/general-gpio-shared-cansleep-0002-pinctrl-meson-restore-non-sleeping-gpio.patch

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -1,4 +1,4 @@
1-
From cd3a7b205c14a4a1ea44de10105e783b7a0baaa1 Mon Sep 17 00:00:00 2001
1+
From 9e027834094551ae19de58e2eada10079693e81c Mon Sep 17 00:00:00 2001
22
From: Viacheslav Bocharov <v@baodeep.com>
33
Date: Tue, 9 Jun 2026 16:37:20 +0300
44
Subject: [PATCH] pinctrl: meson: restore non-sleeping GPIO access

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