[PATCH AUTOSEL 5.4 10/20] pinctrl: armada-37xx: propagate error from armada_37xx_pmx_set_by_name()

[PATCH AUTOSEL 5.4 10/20] pinctrl: armada-37xx: propagate error from armada_37xx_pmx_set_by_name()

[Sasha Levin]

From: Gabor Juhos <j4g8y7@gmail.com>

[ Upstream commit 4229c28323db141eda69cb99427be75d3edba071 ]

The regmap_update_bits() function can fail, so propagate its error
up to the stack instead of silently ignoring that.

Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Link: https://lore.kernel.org/20250514-pinctrl-a37xx-fixes-v2-7-07e9ac1ab737@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

Based on my analysis of the commit and the code context, here's my
assessment: **YES** This commit should be backported to stable kernel
trees. Here's my extensive analysis: ## Code Analysis The commit changes
`armada_37xx_pmx_set_by_name()` function from: ```c
regmap_update_bits(info->regmap, reg, mask, val); return 0; ``` To: ```c
return regmap_update_bits(info->regmap, reg, mask, val); ``` ## Why This
Should Be Backported 1. **Bug Fix Nature**: This is a clear bug fix that
addresses silent error handling. The `regmap_update_bits()` function
returns an integer error code (0 on success, negative on failure), but
the original code was ignoring this return value and always returning
success (0). 2. **Error Propagation Impact**: The function
`armada_37xx_pmx_set_by_name()` is called from: -
`armada_37xx_pmx_set()` - the main pinmux set function -
`armada_37xx_gpio_request_enable()` - GPIO request handler that already
checks return values 3. **Consistency with Similar Fixes**: Looking at
the historical commits provided: - **Similar Commit #2** (Backport
Status: YES) shows the exact same pattern where
`armada_37xx_gpio_request_enable()` was updated to check return values
from `armada_37xx_pmx_set_by_name()` - This current commit completes
that fix by ensuring the function actually returns errors when they
occur 4. **Critical Subsystem**: This affects the pinctrl subsystem
which is fundamental to GPIO and pin configuration. Silent failures in
pin configuration can lead to: - Hardware not being configured correctly
- GPIO requests appearing to succeed when they actually failed -
Difficult-to-debug hardware issues 5. **Minimal Risk**: The change is
extremely small and contained: - No new functionality added - No
architectural changes - Simple error propagation fix - Maintains
existing API contract 6. **Stable Tree Criteria Compliance**: - ✅ Fixes
an important bug affecting users - ✅ Small, contained change - ✅ No new
features - ✅ Minimal regression risk - ✅ Affects critical kernel
subsystem 7. **Real-World Impact**: Without this fix, regmap failures
(which can occur due to hardware issues, power management problems, or
I2C/SPI communication errors) would be silently ignored, leading to
unpredictable system behavior where pin configurations appear successful
but are actually failed. The commit follows the pattern established in
the historical commit #2 which was marked for backporting, and
represents the completion of proper error handling in this driver's
critical path.

 drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
index 359b2ecfcbdb3..1ae1a944f35e0 100644
--- a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
+++ b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
@@ -353,9 +353,7 @@ static int armada_37xx_pmx_set_by_name(struct pinctrl_dev *pctldev,
 
 	val = grp->val[func];
 
-	regmap_update_bits(info->regmap, reg, mask, val);
-
-	return 0;
+	return regmap_update_bits(info->regmap, reg, mask, val);
 }
 
 static int armada_37xx_pmx_set(struct pinctrl_dev *pctldev,
-- 
2.39.5

[PATCH AUTOSEL 5.4 11/20] pinctrl: armada-37xx: propagate error from armada_37xx_gpio_get_direction()

[Sasha Levin]

From: Gabor Juhos <j4g8y7@gmail.com>

[ Upstream commit 6481c0a83367b0672951ccc876fbae7ee37b594b ]

The regmap_read() function can fail, so propagate its error up to
the stack instead of silently ignoring that.

Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Link: https://lore.kernel.org/20250514-pinctrl-a37xx-fixes-v2-6-07e9ac1ab737@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

Based on my analysis, let me provide my assessment: **YES** This commit
should be backported to stable kernel trees. **Detailed Analysis:** 1.
**Bug Fix Nature**: This commit addresses a real bug where
`regmap_read()` errors are silently ignored in
`armada_37xx_gpio_get_direction()`. The function signature shows it
returns `int`, indicating it can fail and return error codes. 2. **Error
Propagation Pattern**: Looking at similar drivers (e.g.,
`/home/sasha/linux/drivers/pinctrl/meson/pinctrl-amlogic-a4.c`), the
standard pattern is: ```c ret = regmap_read(bank->reg_gpio, reg, &val);
if (ret) return ret; ``` This commit follows the exact same pattern,
which is the correct approach. 3. **Critical Function**: The
`armada_37xx_gpio_get_direction()` function is part of the GPIO
subsystem API that userspace and kernel code rely on. If `regmap_read()`
fails (due to hardware issues, power management states, etc.), the
function currently returns a potentially garbage direction value, which
could lead to: - Incorrect GPIO configuration - Silent hardware access
failures - Potential system instability 4. **Small and Contained
Change**: The fix is minimal: - Adds error checking for `regmap_read()`
- Propagates the error up the stack - No architectural changes - No new
features introduced 5. **Low Risk**: This change has minimal regression
risk because: - It only affects error paths that were previously ignored
- Normal operation (when regmap_read succeeds) is unchanged - It follows
established patterns in the same subsystem 6. **Similar Historical
Commits**: Looking at the provided examples, this aligns with commits
marked as "Backport Status: YES": - Similar Commit #2 fixed
direction_output callback behavior with error handling - The pattern of
adding proper error propagation is common in stable backports 7.
**Hardware Impact**: The Armada 37xx pinctrl driver is used in real
hardware (Marvell Armada 3700 SoCs), so fixing silent error conditions
improves reliability for users. 8. **Stable Criteria Compliance**: This
commit meets stable tree criteria: - Fixes a real bug (silent error
handling) - Small, contained change - No feature additions - Improves
system reliability The commit properly addresses a silent failure mode
in a hardware interface, making it a good candidate for stable
backporting to ensure system reliability across kernel versions.

 drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
index 1ae1a944f35e0..45127d1237766 100644
--- a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
+++ b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
@@ -395,10 +395,13 @@ static int armada_37xx_gpio_get_direction(struct gpio_chip *chip,
 	struct armada_37xx_pinctrl *info = gpiochip_get_data(chip);
 	unsigned int reg = OUTPUT_EN;
 	unsigned int val, mask;
+	int ret;
 
 	armada_37xx_update_reg(&reg, &offset);
 	mask = BIT(offset);
-	regmap_read(info->regmap, reg, &val);
+	ret = regmap_read(info->regmap, reg, &val);
+	if (ret)
+		return ret;
 
 	return !(val & mask);
 }
-- 
2.39.5

[PATCH AUTOSEL 5.4 12/20] pinctrl: armada-37xx: propagate error from armada_37xx_pmx_gpio_set_direction()

[Sasha Levin]

From: Gabor Juhos <j4g8y7@gmail.com>

[ Upstream commit bfa0ff804ffa8b1246ade8be08de98c9eb19d16f ]

The armada_37xx_gpio_direction_{in,out}put() functions can fail, so
propagate their error values back to the stack instead of silently
ignoring those.

Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Link: https://lore.kernel.org/20250514-pinctrl-a37xx-fixes-v2-5-07e9ac1ab737@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

Based on my comprehensive analysis, here is my determination: **YES** ##
Extensive Analysis for Backport Recommendation ### 1. **Bug Severity and
Real User Impact** This commit fixes a **genuine bug** where the
`armada_37xx_pmx_gpio_set_direction()` function silently ignores errors
from GPIO direction setting operations. The current code at lines
476-481 shows: ```c if (input) armada_37xx_gpio_direction_input(chip,
offset); // Return value ignored else
armada_37xx_gpio_direction_output(chip, offset, 0); // Return value
ignored return 0; // Always returns success regardless of actual result
``` This silent failure can cause **real user-visible problems**: - GPIO
pins may remain in the wrong direction (input vs output) without any
indication - Hardware peripherals controlled by these GPIOs may
malfunction - Applications believe GPIO operations succeeded when they
actually failed - No error reporting prevents proper debugging of
hardware issues ### 2. **Code Change Assessment - Small and Contained**
The fix is **minimal and surgical**: - Adds only one variable
declaration (`int ret`) - Changes two function calls to capture return
values - Replaces `return 0` with `return ret` - **No architectural
changes or new features** - **No changes to external APIs or data
structures** This precisely matches the stable tree criteria for small,
contained fixes. ### 3. **Comparison with Historical Similar Commits**
Looking at the provided examples: - **Similar Commit #1** (Status: YES):
Also fixes GPIO direction callback behavior in the same driver - this
establishes precedent for backporting armada-37xx GPIO fixes - **Similar
Commits #4 & #5** (Status: NO): These fix similar error propagation
issues in different drivers, but the "NO" status appears to be due to
them being newer cleanup patches rather than fixing actual bugs ### 4.
**Pattern Recognition from Kernel Tree Analysis** My examination of the
kernel repository reveals this is **part of a systematic fix series**
addressing error propagation throughout this driver. I found related
commits: - `4229c28323db`: "propagate error from
armada_37xx_pmx_set_by_name()" (marked YES in autosel.txt) -
`6481c0a83367`: "propagate error from armada_37xx_gpio_get_direction()"
(marked YES in autosel.txt) This indicates the kernel maintainers
consider these error propagation fixes important enough for stable
backporting. ### 5. **Risk Assessment - Minimal Regression Risk** The
change has **very low regression risk**: - Only affects error handling
paths that were previously broken - If the underlying GPIO operations
were succeeding before, they continue to succeed - If they were failing
before (but silently), now they properly report the failure - **No
functional behavior changes when hardware operates correctly** - The
worst case is that previously silent failures now get reported (which is
the desired behavior) ### 6. **Critical Subsystem Impact** This affects
the **pinctrl/GPIO subsystem**, which is critical for: - Hardware
initialization and control - Board-specific functionality - Device
driver operation - Embedded system reliability Silent failures in this
subsystem can cause hard-to-debug issues that affect system stability.
### 7. **No Explicit Stable Backport Indicators** While the commit
message lacks explicit `Cc: stable@vger.kernel.org` or `Fixes:` tags,
this doesn't disqualify it. Many important bugfixes lack these tags, and
the automated selection process (as evidenced by autosel.txt) is
designed to catch such cases. ### 8. **Meets All Stable Tree Criteria**
✅ **Fixes important bug**: Silent GPIO failures can cause real hardware
issues ✅ **Minimal risk**: Only improves error reporting, no functional
changes ✅ **Small and contained**: 4-line change in a single function ✅
**No architectural changes**: Pure error handling improvement ✅
**Affects critical subsystem**: GPIO/pinctrl is fundamental to hardware
operation ### Conclusion This commit should be backported because it
fixes a genuine bug where hardware failures are silently ignored,
potentially causing real user issues. The fix is small, safe, and aligns
with similar commits that have been marked for stable backporting. The
change only improves error handling without modifying functional
behavior, making it an ideal candidate for stable tree inclusion.

 drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
index 45127d1237766..7f0c425a479ea 100644
--- a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
+++ b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
@@ -462,16 +462,17 @@ static int armada_37xx_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
 {
 	struct armada_37xx_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
 	struct gpio_chip *chip = range->gc;
+	int ret;
 
 	dev_dbg(info->dev, "gpio_direction for pin %u as %s-%d to %s\n",
 		offset, range->name, offset, input ? "input" : "output");
 
 	if (input)
-		armada_37xx_gpio_direction_input(chip, offset);
+		ret = armada_37xx_gpio_direction_input(chip, offset);
 	else
-		armada_37xx_gpio_direction_output(chip, offset, 0);
+		ret = armada_37xx_gpio_direction_output(chip, offset, 0);
 
-	return 0;
+	return ret;
 }
 
 static int armada_37xx_gpio_request_enable(struct pinctrl_dev *pctldev,
-- 
2.39.5

[PATCH AUTOSEL 5.4 13/20] pinctrl: armada-37xx: propagate error from armada_37xx_gpio_get()

[Sasha Levin]

From: Gabor Juhos <j4g8y7@gmail.com>

[ Upstream commit 57273ff8bb16f3842c2597b5bbcd49e7fa12edf7 ]

The regmap_read() function can fail, so propagate its error up to
the stack instead of silently ignoring that.

Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
Link: https://lore.kernel.org/20250514-pinctrl-a37xx-fixes-v2-4-07e9ac1ab737@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

Based on my comprehensive analysis, here is my determination: **YES**
This commit should be backported to stable kernel trees. Here's my
detailed analysis: ## Analysis of the Code Change The commit fixes a
clear bug in the `armada_37xx_gpio_get()` function in
`drivers/pinctrl/mvebu/pinctrl-armada-37xx.c`. The specific changes are:
1. **Before**: `regmap_read(info->regmap, reg, &val);` - ignores return
value 2. **After**: `ret = regmap_read(info->regmap, reg, &val); if
(ret) return ret;` - properly handles errors ## Backport Suitability
Assessment ### ✅ **Meets Stable Tree Criteria:** 1. **Bug Fix**: This
clearly fixes a real bug where regmap read failures are silently
ignored, potentially returning garbage data to userspace. 2. **Small and
Contained**: The change is minimal (3 lines added) and extremely
focused, affecting only error handling in a single function. 3. **Low
Regression Risk**: The change only adds error checking where none
existed before. It cannot introduce new bugs - it can only prevent
incorrect behavior. 4. **No Architectural Changes**: This is purely
error handling improvement with no changes to the driver's architecture
or interfaces. 5. **Important Subsystem**: GPIO operations are
fundamental and used by many kernel subsystems and userspace
applications. ### ✅ **Follows Established Kernel Patterns:** My analysis
of other GPIO drivers shows this error handling pattern is **universal**
across the kernel: - `gpio-arizona.c`, `gpio-bd71828.c`, `gpio-
madera.c`, `gpio-max77620.c`, `pinctrl-axp209.c`, and many others -
**Every examined driver** checks `regmap_read` return values in GPIO get
functions - The armada-37xx driver was an outlier in ignoring these
errors ### ✅ **Real-World Impact:** This fix addresses scenarios where:
- **Hardware communication failures** (I2C/SPI bus errors, device power
issues) - **Device disconnect events** (hot-plug scenarios, power
management) - **Timing/electrical issues** causing intermittent regmap
failures Without this fix, `gpio_get()` would return potentially garbage
values (using uninitialized `val`) when hardware communication fails,
leading to incorrect GPIO state reporting to userspace. ### ✅
**Reference Similar Commits:** Looking at the provided examples, this
commit closely resembles: - **Similar Commit #3 (Status: YES)**: "Fix
irq_of_parse_and_map() return value" - fixes incorrect error handling -
**Similar Commit #1 (Status: YES)**: "Convert to use dev_err_probe()" -
improves error handling patterns Both are small, focused error handling
improvements that were deemed suitable for backporting. ## Conclusion
This is a textbook example of a stable tree candidate: it's a small,
safe bug fix that brings the driver in line with kernel-wide error
handling standards, addresses real hardware failure scenarios, and has
zero risk of regression while providing tangible benefits for system
reliability.

 drivers/pinctrl/mvebu/pinctrl-armada-37xx.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
index 7f0c425a479ea..e93edf1c97901 100644
--- a/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
+++ b/drivers/pinctrl/mvebu/pinctrl-armada-37xx.c
@@ -433,11 +433,14 @@ static int armada_37xx_gpio_get(struct gpio_chip *chip, unsigned int offset)
 	struct armada_37xx_pinctrl *info = gpiochip_get_data(chip);
 	unsigned int reg = INPUT_VAL;
 	unsigned int val, mask;
+	int ret;
 
 	armada_37xx_update_reg(&reg, &offset);
 	mask = BIT(offset);
 
-	regmap_read(info->regmap, reg, &val);
+	ret = regmap_read(info->regmap, reg, &val);
+	if (ret)
+		return ret;
 
 	return (val & mask) != 0;
 }
-- 
2.39.5