This is a note to let you know that I've just added the patch titled
pinctrl: qcom: lpass-lpi: fix concurrent register updates
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pinctrl-qcom-lpass-lpi-fix-concurrent-register-updat.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 5f5506a5b7a6ce6c09eeeec81ac326d7cdc8553d
Author: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Date: Fri Oct 13 16:57:05 2023 +0200
pinctrl: qcom: lpass-lpi: fix concurrent register updates
[ Upstream commit c8befdc411e5fd1bf95a13e8744c8ca79b412bee ]
The Qualcomm LPASS LPI pin controller driver uses one lock for guarding
Read-Modify-Write code for slew rate registers. However the pin
configuration and muxing registers have exactly the same RMW code but
are not protected.
Pin controller framework does not provide locking here, thus it is
possible to trigger simultaneous change of pin configuration registers
resulting in non-atomic changes.
Protect from concurrent access by re-using the same lock used to cover
the slew rate register. Using the same lock instead of adding second
one will make more sense, once we add support for newer Qualcomm SoC,
where slew rate is configured in the same register as pin
configuration/muxing.
Fixes: 6e261d1090d6 ("pinctrl: qcom: Add sm8250 lpass lpi pinctrl driver")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231013145705.219954-1-krzysztof.kozlowski@xxxxxxxxxx
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
index dd1c9fd733c8f..ec37ad43a6364 100644
--- a/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
+++ b/drivers/pinctrl/qcom/pinctrl-lpass-lpi.c
@@ -102,7 +102,8 @@ struct lpi_pinctrl {
char __iomem *tlmm_base;
char __iomem *slew_base;
struct clk_bulk_data clks[MAX_LPI_NUM_CLKS];
- struct mutex slew_access_lock;
+ /* Protects from concurrent register updates */
+ struct mutex lock;
const struct lpi_pinctrl_variant_data *data;
};
@@ -330,9 +331,11 @@ static int lpi_gpio_set_mux(struct pinctrl_dev *pctldev, unsigned int function,
if (WARN_ON(i == g->nfuncs))
return -EINVAL;
+ mutex_lock(&pctrl->lock);
val = lpi_gpio_read(pctrl, pin, LPI_GPIO_CFG_REG);
u32p_replace_bits(&val, i, LPI_GPIO_FUNCTION_MASK);
lpi_gpio_write(pctrl, pin, LPI_GPIO_CFG_REG, val);
+ mutex_unlock(&pctrl->lock);
return 0;
}
@@ -438,14 +441,14 @@ static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int group,
if (slew_offset == NO_SLEW)
break;
- mutex_lock(&pctrl->slew_access_lock);
+ mutex_lock(&pctrl->lock);
sval = ioread32(pctrl->slew_base + LPI_SLEW_RATE_CTL_REG);
sval &= ~(LPI_SLEW_RATE_MASK << slew_offset);
sval |= arg << slew_offset;
iowrite32(sval, pctrl->slew_base + LPI_SLEW_RATE_CTL_REG);
- mutex_unlock(&pctrl->slew_access_lock);
+ mutex_unlock(&pctrl->lock);
break;
default:
return -EINVAL;
@@ -461,6 +464,7 @@ static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int group,
lpi_gpio_write(pctrl, group, LPI_GPIO_VALUE_REG, val);
}
+ mutex_lock(&pctrl->lock);
val = lpi_gpio_read(pctrl, group, LPI_GPIO_CFG_REG);
u32p_replace_bits(&val, pullup, LPI_GPIO_PULL_MASK);
@@ -469,6 +473,7 @@ static int lpi_config_set(struct pinctrl_dev *pctldev, unsigned int group,
u32p_replace_bits(&val, output_enabled, LPI_GPIO_OE_MASK);
lpi_gpio_write(pctrl, group, LPI_GPIO_CFG_REG, val);
+ mutex_unlock(&pctrl->lock);
return 0;
}
@@ -642,7 +647,7 @@ static int lpi_pinctrl_probe(struct platform_device *pdev)
pctrl->chip.of_gpio_n_cells = 2;
pctrl->chip.can_sleep = false;
- mutex_init(&pctrl->slew_access_lock);
+ mutex_init(&pctrl->lock);
pctrl->ctrl = devm_pinctrl_register(dev, &pctrl->desc, pctrl);
if (IS_ERR(pctrl->ctrl)) {
@@ -660,7 +665,7 @@ static int lpi_pinctrl_probe(struct platform_device *pdev)
return 0;
err_pinctrl:
- mutex_destroy(&pctrl->slew_access_lock);
+ mutex_destroy(&pctrl->lock);
clk_bulk_disable_unprepare(MAX_LPI_NUM_CLKS, pctrl->clks);
return ret;
@@ -670,7 +675,7 @@ static int lpi_pinctrl_remove(struct platform_device *pdev)
{
struct lpi_pinctrl *pctrl = platform_get_drvdata(pdev);
- mutex_destroy(&pctrl->slew_access_lock);
+ mutex_destroy(&pctrl->lock);
clk_bulk_disable_unprepare(MAX_LPI_NUM_CLKS, pctrl->clks);
return 0;
